As for the cost of an UZI, thats kinda Like asking whats a CHEVY WOTH? Thiere are different models that factor into cost? Most Common now is the Model B, a closed Bolt design, made after the Ban and made to be more difficult to convert back to full or select fire?
Next is the Norenco China made copy of the UZI, most commonly seen with that Planet of the Apes Wood stock? Good news is it will Take a FN or UZI Folder or Wood stock, Bad news is, thats NOT LEGAL! LOL The Most and highest cot on the UZI is the Model A, other than the FN Inport or the Real UZI SELECT FIRE, the Model A can Run ya in the Thousands? Not trying to be a smart alec, but thats the field? Ya need to know the make, Model and Age, then we can Help ya Look it up and determine the Value and what it should cost, over what he's trying to sell it for? Remember Pistol Cartridge carbines, whick the UZI falls into is neather a Rifle or a Pistol, but a mis-match of both? Great for what it was designed for, Poor at so many other things?