Is 450.00 too much for a home appraisal?

I am getting ready to refinance and was just told that a FHA home appraisal on a 150,000. loan was going to cost me 450.00 the last appraisal we got 2 years ago was only 300.00 . why is it so high. I am worried Im getting screwed what should I do about it. we are going through a mortgage broker.