A tap tool is less than $25 on Amazon. I used one with great success on my left crank arm but I agree that it depends on how badly stripped the threads are. If you do try to re-tap the thread, follow the instructions in the comments about how the thread arms are marked L/R, using some lubrication, compressed air for cleaning out the tiny metal shavings, etc.

I had pretty much the same issue with my left pedal/crank arm back in December. I bought one of these thread tools off Amazon and re-tapped the threads. The comments on Amazon are very helpful (about using compressed air, some lubrication, cleaning up the metal shards, etc.) on how to use the tool. I was able to successfully rethread the crank arm and re-insert the pedal (this assumes your pedal threads haven't been damaged). You will need a 15mm wrench to re-tighten the pedal. Good luck!