A 1jz with blown turbo's would not be worth much at all. $800 or less.
i do know of someone who has a genuine low K 1jz for sale . though he (seriously) wants $2500 for it. it includes a manual ecu and loom. The motor has done a genuine 23000k'ms and was only the second 1jz halfcut brought into Ausralia, it has been disassembled and inspected then lovingly reassembled ready to be used in a 600hp application. He is only selling because research has shown that hte single turbo 1jz has a stronger bottom end and will be better in this application.
So if you are serious about geting yourself a good engine
this is the one for you.