And, if I'm not mistaken, gas is really cheap in Saudi Arabia.
So it's not adaptable in another country where you have to pay big money for routing goods. He would have spent his whole benefits in gas.
Not entirely true. Maybe not onions, but I see this business model -- buying very cheap in bulk and selling at a slightly lower price than the lowest supplier price (while still making a profit) -- everyday on amazon on all kind of products.
People buy items in bulk from Ali Express (Alibaba's business unit ) and sell on amazon using the same business model the OP has implemented.
I even tried it a while back and it was fairly successful / profitable.
ex: Stawberry Corer / Huller : https://www.amazon.com/s/ref=nb_sb_noss_2?url=search-alias%3...
A bunch of "brands" are selling it for 7$ to 8$. I found the same on Ali Express for 79 cents a piece, bought a 100 and sold them off to for 4$ a piece (with free shipping, it's just a few ounces in weight) a few months back...
He deleted it, most likely because -- like @ flashman has stated somewhere here -- that other's might cut in on his business in Saudi Arabia.
Also @flashman's TL;DR is on point. I guess it's a matter of finding the arbitrage, and can be applied to almost any "not so sexy" product in any country, the key is to find it, and keep it to yourself :)
- Saudi Arabian resident spotted an arbitrage opportunity buying onions cheaply and selling them to small and mid-sized outlets (large outlets already had suppliers) - reinvested profits to grow the business (more onions, truck to move them, expanded to another province)