Those are two very different cameras, with very different price points. The S5 Pro is more expensive then the 450D. You might want to get the 50D at that price instead, if you are looking at Canon.
Is your warranty over? Sounds like you might have damaged your lens.
actually the price of the S5 body and the 450D kit is the same.
hmm i still got 6 months warranty, should i go send for repair?