1600:1 contrast ratio?

I am considering a purchase on a 47" Vizio 1080p LCD HDTV but I noticed it has a pretty low contrast ration of 1600:1 compared to other tv's that are a lot more expensive such as 7000:1. Should I say no, and not buy the vizio just because of the ratio...is it really such a big deal? I don't really understand the whole concept of the ratio anyway. I appreciate your respone.