I work at a large hobby shop and we stock alot of boat parts. Are you looking for a nitro pipe or a muffled pipe. We have the CMDI muffled pipe that is great for 80 size engines. We sell it for $63.99 plus shipping. Do you need a header as well? If so,for what engine.
I have a great .80 pipe. Never been cut, has an aluminum weld extension so you'll have options to shorten the pipe if you need to. Here's a picture, hard to fit with my camera but money back less shipping if you don't like it.
Muck 80 pipe with MHardware muffler, 90 degree pressure fitting, and coupler. Basically as you see it. $50 shipped. I just pull two of these out of my twin. I have no need for them both.