It's on sale now for $119.99 without the coupon, if you use a 20% off any single item coupon (you can find them online) with the sale price it's 95.99. This way you save another 4 bucks to spend on some other HF stuff.
I normally don't buy extended warranties but I've heard HF is pretty good about the replacement of these engines, they just give you a new one. I bought the extended warranty on the 99cc one I just picked up. 2 year extended warranty was around 19 bucks. Do you guys buy the 2 year extended warranty?