That's every price guide. Price guide is to give you the value of an item, not what a comic book store would buy it for. If you sell something to a comic book store, you're always going to get less than the actual value, because they have to resell it. The only reason to sell something at a comic book store is because you need money now and don't want to deal with ebay.

Yes to 1 and 2. Don't know about 3.