The C series are the early ones and have much nicer blue than the F series. They are my personal favorites. $600.00 is about the average high asking price. In the overall scheme of things $50.00 is not that much, but I would feel more comfortable at $550.00. I have never been able to figure out why the "3rd" Gens seem to bring such outrageous prices. I think it is because they are the "Signature" series and people, erroneously, attach some significance to that and because they come in a large, pretty, grey box. I would much rather have a 2nd Gen C series Colt.