Is it Blasphemy to want to sell SMG2 to help get Sonic Colors?

First off, I really really want Colors, like super badly. The problem then in lies that I'm currently too poor to just go out and purchase this game, with no consequences. But I do have a recently completely beaten SMG2.

So I've completely destroyed SMG2 and its predecessor. Got all Green Stars, including the 2 power stars in Grandmaster Galaxy and I've beat 1 with Luigi and 120 stars.

So is it wrong to trade it in to help get Colors? I mean, Colors is New, and I don't feel like simply replaying Mario. But part of me thinks this is wrong. <_<

Just ask yourself one question: Will you be going back to play Super Mario Galaxy 2 much anymore? As you say, you've completed it and solidly too. People tend to hang onto games just for the sake of owning it, which can often mean they lose out on a title they may have really enjoyed. And I would definitely say this title is worth trading in for, if you feel you're done with the other one.

Uh, it's a good game. It's net-wide accepted as the best Sonic game since the original titles. Just because you don't like it, doesn't mean most people don't either.

If you're done with a game, there's nothing "silly" about trading it in to get a new title. Dust collectors don't provide any sense of enjoyment.