In my opinion, there are 4 methods of restocking. First, the Neopian shops, then the User-owned Shops, the Auction House and finally the Trading Post. This guide is going to go through each and every single method of restocking so that you will be able to get the best deals. Personally, I never really liked the Neopets games too much, so almost all my money came from restocking my shop. Hence I know most of the tricks in snatching that codestone real cheap.
The Neopian Shops
These are the shops you find spread out all over Neopia, that are not owned by neopets Users. Almost all shops in Neopia have a certain theme to them. Here I will go through how to shop at these Shops, and which shops are good for restocking as well as which aren't. Whilst restocking, always have at least 10k with you (I usually go for 50k) in case you run across a really awesome deal.
Firstly, generally all Neopian Shops restock at roughly the same time, though there are some delays here and there. Now, to "Power Shop" or "Restock" useing Neopian Shops.. Firstly, open at least 2 windows (I use 3). Set one to the Shop Wizard. Make sure you have set the search criteria to Search for identical phrases only. Then set your other window(s) to a Neopian Shop. I usually use the Book Store and the Healthy Food Shop. It's actually quite fasinating how slowly perfectly good items sell in the healthy food shop. Most people get all obsessed with the other Food Shop, which leaves the good old healthy one nice and empty. I can usually buy 5 to 8 Organic Green Apples for roughly 150np profit each. Also I can get several other items per restock, usually 15-20 items per restock, with a profit of at least 100-200 np each. Hence, that's a minimum of 1,500np per restock, though usually it falls closer to the 3,000np lines. Not a lot? Yes, that might be true, but it's profit none-the-less. I prefer a consistent, guarenteed small profit to a lucky shot at luck-based stores such as the Petpet store. It is only rarely that you will find a good, cheap petpet there to make a profit with. Also, I like to 'multi-restock' which will be explained in a later guide.
Finding the perfect restocking shop is not easy and I really can't help you much here. Just waste a restock or 2 looking up the prices of items you see commonly in certain stores. Decide which store is most profitable for YOU. Some people prefer a store where there is one or 2 items to watch out for that will give them a profit of several thousand neopoints. Per restock they only get one good item or, if they are unlucky, just a few not so profitable items. Or the other choice would be a store. It also depends on your concentration, how much you are doing at once (I would NOT do the one-item-restock while chatting to 5 different people), and on your internet connection. Of course, there are some stores that are absolutely terrible for restocks, such as the Grooming Palor. I would choose 3 shops: 2 for your regular restock, and one that sells out relatively slowly in case both of your other shops have sold out or only have "bad" items.
The Trading Post
The Trading Post is a good, often forgotten, form of restocking. First, let's leaf through all the junk that is traded at the trading post and find what we actually want: Codestone Lots, Bottled Faerie Lots, book lots (worth over 10k), Paintbrush lots (for the richer Neopians), good petpet lots, ect. You can skip right over the jelly and dung lots. I usually write down the Codestone and Faerie prices and update them every few days. This way, I won't have to search everything on the shop wizard (and doing so get banned from the shop wizard for a short period of time). Anyways, let's say you are offering on a lot of codestones worth a grand total of 27,545np. Often you will be able to offer 25k or so. Always offer in cash unless the owner of the lot says otherwise in their wishlist, or its pretty likely that your offer will be rejected. I generally advise to sell items in your store rather than at the trading post, unless it is too expensive to be sold at your store. Watch out for scammers who will try to trick you with cheap items that look similar to very expensive items. Also, always be sure to double check your prices on the shop wizard as prices change very quickly. That's about it for the trading post. Just one more thing: make sure that you bid mainly on newer lots as you will get a faster response from those.
The Auction House
Another one of those not-so-often used deals. Now, a lot of people try to use the auctions to get codestones and faeries. HOWEVER, it is very rare that you will be able to get a codestone there cheaper than through the shop wizard for the simple reason that there are many people out there who have the same idea. It is much more advisable to search through the less popular items such as, say, a Painted Petpet or a really expensive food item. Try to ensure that your profit consists of a minimum of 500 NP, otherwise it would hardly be worth the bother. This works best with unpopular rare items that are still easy to sell. Basically, I consider auctions a great way to make some extra money on the side without investing lots of time and effort into them. You will easily be about to make 5k plus on Auctions if you buy items cheap there and re-sell them for a higher price in your shop. Just make sure to write down when the auction is ending and how much the maximum that you are willing to pay is. Then, go there about a minute before ending time and bid an "odd" number (such as 453 instead of 450 or 312 instead of 300). This makes it more likely that you will win and the 10 NP aren't going to make that big a difference.
User-Owned Shops