


So I've gone through pages of text without actually stepping into a shop. Guess it's about time since you must be tired of reading about technique stuff. I will begin with a basic run-through of successfully restocking an item and then discuss finer details after. You can click on any resized images to see the screenshot in original size (this way you can see how big the text actually is).
I pick my shops, and refresh them repeatedly until I see the shop has restocked with items worth buying. In this example, I have caught a nice restock in the magic shop:

I went for the Faerie Grundo because it was the first one that caught my eye. So I click on the item image and get a javascript prompt: "Are you sure you wish to purchase Faerie Grundo Morphing Potion at..." (I forgot to take a screenshot of it)
I hit the spacebar right after it pops up. Don't bother taking the time to read it. The next page that loads is the Haggle page. Here you must enter a number relatively close to the asking price of the item in the textbox. Then you click the pet asked for in the picture below. You must do both to successfully purchase the item, AND you must do both faster than anyone else in that shop.

If you are successful in your purchase upon clicking on the pet, the next page that loads tells you your offer has been accepted:

If you were not the fastest one to finish, you will get the Sold Out page: