This was initially requested about a year ago, and I have only just thought myself brave enough to traverse the 07Wiki DOM... So here you go, Store Profit! We have scraped all the stores in OSRS, along with their items, and have them available in a list view to see how much you can make buying and selling them. Many of the items will have a low trade volume, maybe once or twice a day, but if you manage to sell, then you will be looking at a huge ROI!
For Premium users, there is also a custom filter to only show F2P Stores only.
Discuss this update on the forums