I dont know if you can get one _new_ rebuild might be your closest bet.
Jasper sells rebuilt motors and transmissions. Might want to look up their web site, i believe you can get prices there.
However, thats the motor, not all of the accessories. You'll usually need to buy fuel delivery, water pump, alternator, PS pump, starter, filters, and whatnot separate. The good news is, i belive the 89 is TBI, so there's no computer to worry about.
I have a 90 2.5L in my basement if you're interested in that. I'll sell it cheap, as ive never run it myself. It turns, and before i disconnected everything I had it cranking with the starter. It needs some clean-up, and a new throttle body. Otherwise, as far as I know, its in good shape, or so i was told by the guy that gave me the jeep it came out of. Not sure where you are, but pm me if you want to entertain the idea.