Six months later, though, the price of tomatoes collapsed.
Farmers suddenly were only getting seven US cents (5p) per kilo, and Susyono started wondering if he'd made the right decision.
He went back to his neighbour and asked him to go with him to the mountain to look for gold.
The two of them went, with Yono and another friend, up Mount Botak, once again carrying their panning equipment.
They spent two weeks searching, digging and panning, before finally they found it - a lump of gold, about a gram.
“We were so happy and excited!” Susyono recalls laughing.
“We tried to grab as much as we could, snatching whatever we saw,”
Even though they didn't think anyone else was around, they realised they needed to keep their voices low just in case - they didn't want others to know about their find.
With the proceeds from his first haul of gold, Susyono bought food for his family for the Eid al-Adha festival.
Every day they sneaked into the mountains, hoping to find more gold. And as each day went by they found more and more until they had collected 27 grams.
But then something happened which changed their entire enterprise.
“People found out,” he says. The game was up.
It was Kuswanto, the head of the village, who found out about the gold first.
In 2011, he too had been a farmer and rock collector.
“I'd been quite suspicious for a while because they both stopped working as farmers. I saw how caterpillars had eaten up their vegetables,” he says.
Every time he asked them what they did instead of farming, they would say they were busy collecting rocks.
“But I always said, 'Where do you collect rocks?' I knew for sure there wasn't any rock collecting activity at that time because we only collect rocks when there's demand.”
He asked Susyono's wife where her husband was, but she wouldn't tell him.
Then one day, one of Kuswanto's employees told him that they had stopped working because they had discovered gold in the mountain.
“That's nonsense, I told them. There's no such thing as gold in the mountain here in Buru. Stories like that are only fairy tales,” he says.
“But as I went to Yono's place to see what he was doing during the day, I didn't see him. Surprisingly, I saw a new refrigerator and a TV. I also saw his kids playing with mobile phones.
“That really made me curious. I knew Yono hadn't had all those things before. He was poor.”
So Kuswanto quietly followed Susyono and Yono when they slipped up the mountain one night.
Kuswanto struggled to keep up with them, and the batteries in his torch started to dim. By chance he spotted a third person by the side of a creek on the mountainside.
“I didn't know him. I suspect he was one of Susyono's friends,” says Kuswanto.
Intrigued by what the stranger was doing, Kuswanto edged closer and watched in silence. The stranger was panning for gold.
When the man took a break, Kuswanto asked if he could use his tools to pan too.
Kuswanto went home that night with some grit which contained gold.
“I told my wife about the gold and she said I should concentrate on farming.”
But a week later he was back up Mount Botak with his own tools.
“Though when I got there I was really surprised. The mountain was full of people busy digging for gold!”
Buru is rich in flora and fauna, but the island has a violent history.
In the 1960s and 70s, the government detained about 12,000 people there - as part of a country-wide crackdown on suspected communists.
And in early 2000, there were clashes between Muslims and Christians - but after that the island started to enjoy relative stability and peace.
A tropical evergreen rainforest covers Buru.
The island is home to 25 species of mammals, at least four are unique to Buru and the neighbouring islands.
There are also about 178 recorded species of birds.
Like many Indonesian islands, Buru Island was once colonised by the Dutch and Portuguese.
Even before the Dutch arrived in about 1600, Buru was known as a producer of eucalyptus oil from Swamp Tea-tree.
The oil is used to relieve the symptoms of a cold, and is said to keep the body warm when a patient is ill.
But a 30ml bottle only fetches about $3.86 (£2.50).
Despite the island's natural resources, almost 40% of Buru's population - about 40,000 people - live in poverty.
Four years ago, most residents typically earned about $2.32 (£1.50) a day from farming. But once Susyono's secret was discovered, things began to change.
Word about the presence of precious metal in Mount Botak spread quickly.
Within days, people came from across Indonesia to seek their fortunes.
Companies from China and South Korea moved in to build smelters.
Island residents from all walks of life turned to gold-digging - even teachers. For a while, so many had abandoned their classrooms that there was a shortage.
And people found what they were looking for.
Many became wealthier than they had ever been.
They built better houses and bought motorbikes, something which, until then, had been a luxury.
But before long, the influx of professional gold diggers from other parts of Indonesia made it harder for the amateurs.
Teachers gradually drifted back to their classes. Other islanders, who didn't have the right skills, became labourers rather than entrepreneurs.
They worked for 12 hours a day for someone else, in dark mineshafts. And the mineshafts, owned by newcomers, were not regulated.
But it was those newcomers who made the most money.
Many islanders became envious, and crime levels started to rise.
“People now owned expensive belongings. And with this, we saw new cases of burglary,” Kuswanto says.
There were bigger problems too. There were disputes over who could dig where.
Violent clashes broke out, and people died. Buru once again saw violence.
To try to restore peace, in November 2014, the local authority told people to stop digging at the illegal mine on Mount Botak, but it was ignored. The digging continued.
Buru's remoteness - 2,260km (1,404 miles) from the capital Jakarta and in a sea of 17,000 other islands - means that it is difficult for central government to police.
Susyono says he was blamed for creating the gold rush and the resulting violence.
The government was never happy with my discovery. They said if it hadn't been for me, people wouldn't be dying there in the mountains. They also blamed me for the damage to the environment the gold mining has caused.”
Despite his new-found wealth, Susyono's nervousness started to resurface.
“My wife once accompanied me to the mountains to dig gold. And when she saw how dangerous it was, she prohibited me from going there again. She was afraid I would fall and die, especially since she heard about accidents in the mountain.”
He also developed an eye infection. He began to think of it as payback for the time he had spent digging.
After all, the old man in his dream had warned him that there would be a price.
So, Susyono decided: no more digging.
“It wasn't an easy decision because I did make a lot of money. But ultimately, I believe the money that I get should come from something good. It's better not to be rich than have money from an unwanted source.”
He has returned to farming, and still collects rocks once in a while when there is demand.
He also used some of his money to set up a small grocery store in front of his house.
He has never regretted the decision.
The Buru authorities don't regulate or monitor the use of mercury and other substances involved in gold extraction, but most of the mercury that enters Indonesia does so illegally.
There's also an added level of risk.
In May this year, Indonesia's president Joko Widodo decided Buru should be one of the country's “rice granaries”.
Rice is a staple food for Indonesians, but Yuyun Ismawati warns that contaminated water in rivers could transfer to the paddy fields.
Rice from these fields would then be distributed across the island and to other parts of Indonesia.
And then, there's another worry.
Susyono's gold digging may have started on the surface of the mountain, but now miners often have to operate up to 40m underground.
They work with limited oxygen and mostly in the dark.
Shifts usually last 12 hours, and even getting to and from work can be dangerous - some islanders have fallen from the steep, narrow mountain paths.
Limbs have been broken and lives have been lost.
The digging has also led to land erosion and landslides - during the rainy season accidents seem to be more common than they once were.
The landscape of Buru has visibly changed.