Welcome to our forums! However, you should know that your post looks an awful lot like an "offer to sell," which we strictly confine to our Marketplace forum (and there are limits on who can start threads there...).
It would have been better if you'd just asked a more general question like "How can I get a decent price estimate for my November '07 iMac? Here are the specs..." See the difference?
Anyway, I think you've gotten some really good information above, and I hope you'll let us know what Mac you're going to replace the one you're selling with. Again, welcome!