Got mine brand new, out the door for $350 with 2 mags. As always with a used firearm, I'd find out the bottom dollar price from someone in the store that could deal and go from there.
As far as the break down of a CZ100, it's as simple as any other CZ, so no issues there. The trigger will be the kicker- some hate it, some dont mind it. Mine is long but very smooth and crisp, like that of a DA revolver. There is some very informative trigger fixes in this club that I used with great success. I bought mine with a buddy of mine and we both shot it, that day. Did the trigger fix directly off this forum and we shot it again a couple weeks later and he was very impressed with the difference.
I carry mine daily and shoot it weekly and could not be more pleased. The trigger to me, is exactly what a concealed handgun trigger should be- draw-point-pull. With this trigger there is very little chance of accidently engaging the trigger when reholstering the weapon as other brands have been known to do.
I did swap out the plastic guide rod with a steel one and upgraded the recoil spring with a 22lb glock 19 spring for less that $10. A little polishing on the feed ramp for GP and cut my own cross grove on the bottom rail for a modern light attachment. Mine is chambered in .40s&w and has a ported barrel.
If its chambered in a .40s&w with a manufactors date of 2002 or higher, I'd go for it. This would be the newer model -CZ100B. And if your not happy with it, write me a line here on this forum and I would be glad to entertain a offer to take off your or your friends hand, as you can never have to many CZ's.