To me, if the guy isn't worthy of a 3rd round pick, I wouldn't bother. How can someone say "yeah, I like this guy, he could be the one...but only in the 5th." If you are a team that is set at QB, I can understand that approach, but if your team is adrift at QB you are probably going to have to reach. I don't think a 3rd is a huge risk.
But again, if the guy isn't at all worthy of a 3rd round selection, don't bother.