Nope a stroker motor is kinda exspensive to build.I have enough good parts to build a Single Port 1600. You might find a complete motor for that price but odds are it'll be junk. You could rebuild one for that amount probably if you had something to start with.If you use used parts you could get by with re-ringing the pistons,new bearings,hardware,and gaskets and come out with a decntly reliable motor for around what your wanting to spend.
I'm doing this exact thing to a motor right now for someone else. I'm still in the needs guidance stage of motor building. :lol: But I have the right people for the job.
I doubt you will find a good motor around here for $300 that runs. I know me and another local guy have some shortblocks and long blocks you could work with.Maybe somebody else does but I haven't seen any. If your interested and mechanicly inclined,i can get you what you need to get started.