When you click on links to various merchants on this site and make a purchase, this can result in this site earning a commission. Affiliate programs and affiliations include, but are not limited to, the eBay Partner Network.
You can search around the forum and find plenty of info on this topic. Buy what you can afford.
There are differences in each year model.
The powertrain changed in 08. The 2008 has the LS3 6.2 liter V8 with a little more power than the LS2 6.0 liter found in the previous C6 Corvettes. They also switched out the transmission from the T56 to the Tremec 6060 in 2008. It's supposed to be a more solid transmission.
If you can save up for a 2008, then I would recommend that.
While I have an '05 and absolutely love it, my advice is to get the '08. As mentioned, the '08 has the LS3 engine which is newer technology and a little more power. The transmission is built better. The enterior aesthetics are nicer and the entire car is more advanced in general.