You can get a really good engine from a junkyard for about $5,500. Some will include a guarantee, usually 90 days. Some independent shops will warranty their labor as well when installing a junkyard motor...so if it's bad they put in another for free. I would count on a bit more than a grand for swapping motors.
Check out this web site for used motors as an example, (there were quite a few in the Midwest, including one with 15k miles):
Car-Part.com--Used Auto Parts Market