Hello. It is usually more cost effective to replace the engine with a used unit. As for labor time to replace the engine, Motor labor guide gives 12.7 hours. This charge will of course vary depending on the labor rate of the shop you use. Most charge $50-$60 an hour.
As for the cost of the engine, these guys http://www.evansautomotive.net/ have one for $1000.00 with 50,000 miles. They may have others with more or less mile depending on your budget, or you may be able to find one in your area to save shipping charges
I hope this helps you, but if you need anything else, please let me know.