Conversion is hard to beat if you're using a used bike to start with... Here's a used one in your price range that you could probably test before buying.I considered the conversion route, but with parts and labor prebuilt ends up being a better deal. Another consideration is the backlog most shops around here have on major work.
In the long run I’ll probably have a nice mid-drive built by a local frame maker but right now I want to get the bike I can afford and get today (or at least in the next 2 weeks)
GT aggressor pro 27.5 with bafang Luna Cycle BBSHD 1000watt mid drive motor. This bike really does well off road, in the single track, and on hill climbs. Geared for climbing but has plenty of top...