I think I am getting screwed......

I had new struts put on March of 2001 and now my car has started to shake when I go above ~75. I thought it might be my tires so I took it to a tire dealer (not the one that put on my struts) and they said that it needed new struts and tires. ~$800!!!! I know I am getting screwed by one of these guys. I tried calling the dealer that put on the struts but they won't be open till Tuesday. Thanks for any help you'll can offer. Paul