To add to rudestuff's comments -> I did a helicopter CPL add-on in about 70 hours. Was all great and the school i trained with had Bell47's. Problem was the school shut down only a few weeks after i finished and i was kinda stuck. I wanted to do an instructor add-on, but the only other school around me had R22's. You need at least 200 hours in helicopters to instruct on an R22. I reached out to other non-R22' schools around the country, but to them i was 'only' a 70 hour pilot and no insurance apparently would cover me. So even doing it the 'efficient FAA' way with an add-on, you are stuck with an expensive hour building problem.