That is a Tech 4 version of the venerable Duke. The crankshaft is of slightly sterner stuff and has a big gear wheel on it to run the harmonic internal balancer thingy and the oil pump. The block has a little more nickel in it that an 86, and the TPI bore is larger than previous versions. It will produce 94hp but can be beefed up to around 110 with some good porting work by you, especially the exhaust porting.
Asking for a price of an old Duke is tough as you can get the whole car PLUS the engine for really cheap. I have paid a total of $715 for four Fieros, of which three ran. (2 '85's, an '87, and an '88)... So, I would say... $200 for the engine. That is what I would pay, max. Is there anything wrong with the engine? Has it imploded by throwing a rod (common!) or destroying its dynamic balancing set up below the crank? (min. $186 for another unit.) Does it have the whole wiring harness. and further, the computer module for the engine? If so, then you are a gasket kit, ring set, bearing set, a crosshatch cylinderjob, and a valve job away from a rebuilt Duke.
Use these problems I have discussed as bargaining chips for lowering the price.
Gary