Some buyers keep the finished model, and some give it back. It is getting more and more common that the buyer gets to keep the item. (It states in the contract what it's going to be). In some ways, I'd rather have the item back, especially when it's something I would like to use like a bag or a hat. Other times, I'm ok with the buyer keeping it because, let's face it, who has room for all those afghans! If the buyer is going to keep the finished item, I keep the swatch (more on keeping swatches another day). I have several models that were returned to me after the book/magazine has been published. What do I do with all those models? If it is a purse, I use it! If it is an afghan, I have some choices.... use it, give it, donate it, sell it. Some designers sell their models on Etsy or in fairs. The actual project can be sold as long as you don't sell the pattern, which more than likely, now belongs to the publisher. However, it wouldn't be kind to the publisher to 'mass produce' the item to sell. You want the book/issue your item appears in to sell well for the publisher. Many times I donate an item or two to our Church Festival Silent auction. Many of my "sold" models are in my closet, still wrapped up because I can't decide what to do with them!
The photo is Chief, who at a local Church festival, spent all his "game tickets" on face painting. He also had a spider painted on the other side of his face. He was very happy with his decision.