I think collecting sealed DC is very doable. There aren't that many US DC games, and most aren't all that rare, so as far as sealed collections go it'd be a relatively easy set to complete.

The question is if it's what you want to do, or are you just burnt out on collecting. If it's the latter, i'd agree with what was said above -- just put the games in a box in the closet and wait until you're inspired again. No reason to sell them unless you really need the money. If you want them later, you have them!