You may get a good sum like $500 for someone wanting a 'mint' CZ 75. To me, it depends on the finish. If it is blue, then $500 is probably fine - it wears OK, but on the old one it looks GREAT! If it is black paint - no - not for me. If used at all, they will just chip and look like a $250 gun in no time. I'd rather buy a $250 CZ75 and refinish it. BUT - some folks will pay a good sum even for a painted model and sit it in the safe.
On the CTs - if I were interested in a nice CZ75, I would NOT want to pay for the CTs. EVen if I liked the CT grips, I'd rather buy separately unless they came at a real steal with the gun. Then, you don't make out as well.
Also, if you really want a premium on them for the 'mint' condition, box and papers, etc. are a must.
The best feature going for you are the three mags!