Here's why this is a deal. Just go look at the completed auctions for Xbox copies on eBay. Just look at the "very good" listings. A bunch of them ending for between $60 and $75 for copies that even mint or near mint. With CAG16, you can get this for about $50, plus tax. If you have EDGE card, you'll get less than $50. Thus, it's a deal. And as was probably already pointed out, if you get it, and the game isn't complete, or it's all scratched up, you can return to any GameStop store.
Now, do I think a lot of CAGs would be interested in this? Doubt it. But there are plenty of deals that are posted that many CAGs probably wouldn't be interested in. As long as it's a deal, though, it should be posted, if someone comes across it.