An engine will cost you anywhere up to $800. You can check
www.car-part.com or
www.lkqcorp.com (they offer a 6 month warranty) for an engine. LKQ will ship for free to a repair facility, or $125 to a residence. I believe shop time to replace the engine is around 16 hours. It just depends on how much money you're willing to put into it.
The labor and parts to repair your current engine will probably be as much as just replacing the engine in the long run.