if you're looking for a safe buy and general BE point-marginal profit-esque buys then I'd say The Bakery isn't too bad. Although since a few months ago when the restocking are every 2 minutes thing happened most products with profit attacged to their names were thrown back a good 3-4k, theres still profits to be gained.
As with all restocking newcomers(or old comers going to a new shop), you watch before you do. By watching you'll develop a good sense of what is good and what is bad(The faster it goes, the better the profits, usually). Restocking doesn't have any big super secret to it--it's all timing and Internet Connection. So don't fret if everyone but you seem to be making these amazing 100k profits every time they restock(because there probably extravagating or have been sitting infront of the computer for hundreds of hours waiting for that Freezing Potion to appear :-P)
You'll get better as time passes, It's an aquired art.