Might try the GP forum as they have a larger FWD following.
For that price its worth coming and getting it.
You can find a good motor on
http://car-part.com/
bought one for the GTP for $200 minus SC,looked like new inside.
Heres 2 in PA,with 60,65K for $900
2000
Engine
Buick Park Avenue RDY,W321,12-99,3.8SPR CHG,AT,FWD 65,000 A D0866R $900 Al's Auto Parts, Inc. USA-PA(Trevose) E-mail 1-888-396-2199
2000
Engine
Buick Park Avenue RDY,W-321,7-99,3.8SPR CHG,AT,FWD 60,000 A D4103G $900 Al's Auto Parts, Inc. USA-PA(Trevose) E-mail