This achievement will undoubtedly unlock in a regular complete playthrough, and will not require you to go out of your way for it. If you are looking for a quick way to get the achievement, read on.
The fastest way to get this achievement is to sell the cheapest thing in the game, empty shells, to Francis, the wandering merchant (Onion head guy). You can then re-buy them from Francis for a net loss of only 4 glim per shell. Repeat the buy/sell cycle until you've sold the same empty shells 200 times and the achievement will unlock. Assuming you sold nothing else, it would only cost a total of 800 glim to get this achievement the first time you meet Francis.
If you are starting from the beginning and want to get this achievement as fast as possible, just do the main quests, stopping for crates along the way. You will also have to pick up some empty shells that appear on your boat's hull as you move through the water. You will be able to sell the valuables from the crates to Francis when you meet him for the first time after about 1-2 hours of gameplay, and have more than enough glim to get the achievement right away.
Along the way, you will also unlock:
Despite the achievement's description, re-buying stuff from Francis also counts.