I look at LOTS of stuff used on Gunbroker daily, including CZ, then check Kentucky Gun Company, and can often get new in the box for 2% over used with warranty, free shipping, $25 local FFL, not tax (out of state).
Armslist may also be useful if you are in a big enough state (don't try to buy a pistol from someone in another state without an FFL dealer involved at BOTH ends of the transaction, because under Federal Law, pistols are EVIL; rifles and shotguns not so much).