Restocking (Buying) at Neopets Shops
Unfortunately, I do not know much about this subject. You can make a ton of money though, whereas in auctions, the most you can hope to get on one auction is 100k-200k usually, you can find items worth millions if you buy from these shops and "restock" them into your shops or put it up for auction. I actually did try my hand at it (look on the bottom of this page) but it's not much. I am way better at auctions.
A couple tips I learned to increase your speed are to turn off images, or to have the number pre-copied in your clipboard (ctrl V). There are many more, but like I said, I am not a restocker, I'm an auctions sniper and a trader.
I will post the hints that people gave me over neomail and email. I, myself do not understand some of what is said though. I'll just let you read it, and hopefully learn something.
In retrospect, I should have learned how to restock, because a lot of people make a lot of money. However, there isn't that competitive and challenging aspect that you get competing with fellow neoland players in auctions. Sure you are competing to buy cheap items in neopets shops, but in auctions, you can actually see who is bidding what, and who beat you to it.
Anyway, here's advice from 3 different people that helped me out.
When there was an auctions bug, I stopped doing auctions for a little bit, and tried my hand at restocking. I never got anything really good, but here are some tips that I have for you. I restocked at the magic shop (I know a pretty elite one for a newbie restocker) but I did get a lot of motes and novas. I didn't get anything really good like rare morphing potions, but that was cause I only tried this for a couple of weeks until they fixed the auction time bug (where you could bid after the auction closed).