'57 Tbird Value? Help!

Hi,

I've been interested in buying a '57 Tbird for awhile now and I'm trying to get a good estimate of what other cars have gone for before I actually bid on one. I found this interesting website online called collectorcarnet dot com which sells a database of actual classic car sale prices and I'm considering buying it to help me with my purchase. It looks like a pretty reliable website, but I was hoping to get some feedback first. Has anyone used this website and bought their database before? What did you think?

Thanks,
Brooke