RE: 50cc engine choice
The price with wrap around muffler, I believe was $679.00, but you would have to call Taurus to verify this.
Based on my experience with this engine, the price is not an issue when you consider the performance and reliability. I am currently running this engine on an old Funfly RoadRunner that I built 18 years ago, even with it right at 17lbs it will hang on the prop at just under 1/3 throttle, and most of the flying is done at under half throttle.
I looked at all 50cc gas engines that are available before I purchased the Tarurus, and I did considerable research on RC Universe, as well as other forums, and I have yet to find a single person that has been unsatisfied, or has spoke negative about this engine, which is saying more than a lot of other 50cc gassers can.