Skipping anatomy scan?


I am a FTM, 20 weeks along. I had an appointment with my OB on Monday, where he did an ultrasound and told us our baby's gender (its a boy!!!) And said he would like me to go to the hospital for an anatomy scan. He didn't seem to find anything concerning on his ultrasound, and has been saying all along that my pregnancy is normal and healthy. So i got an appointment at the hospital for yesterday(Friday). They called me Thursday to confirm and get all my information and whatnot and told me that my portion of the payment would be $500! When I've gotten ultrasounds from my doctor i havent had to pay anything!

My question is; would you go ahead and get the anatomy scan? Or skip it? We aren't going to terminate if anything is wrong with our boy, so is it really necessary? I would love to see my baby again and have the reassurance that everything is going well, but $500? Thanks for your input.