$800?!?!?!??!?!?!? They saw you coming!!!
The PTO sells direct from CCC for $613.92. Here, check it out. Item #1, click "add to cart" and it will give you the price:
http://www.cubcadet.com/equipment/AR...0-A/0017900014
So, the PTO shuts off? Or the engine dies? If the engine dies, why the heck would you replace the PTO????