The highest power to dollar ratio is got by building a bike. Pre-made bikes as very expensive right now as you point out. If you just want to try one out, go to

The highest power to dollar ratio is got by building a bike. Pre-made bikes as very expensive right now as you point out. If you just want to try one out, go to a bike shop and test drive one. If you want one for yourself and you want it to be fast or go long then I would suggest building a battery pack with headway lithium iron phosphate cells, a lyen high power controller and a solid hub motor, maybe a crystalite. Endless sphere has endless documentation on how to do it. I don't know what your background is so there may be a learning curve, but I can say that you should learn that stuff if you want to get into ebikes anyway. Unless you want to wait 5 years for prices to fall.