hello mike :
you have many decisions to make : on road -off road... petal assist / throttle controls / ////// size = portability .//// ///.price/ reliability.. hub motor / mid drive// look twice at battery -style/power /availability many are proprietary. ...safety- brakes..(get great brakes) ... if you drive at night add lots of lights..
If you buy a cheep china bike (like I did)..expect cheap china parts (they are almost disposable.. )
the battery is where a lot of the cost comes from..( they start at about $200 alone and go up from there..) (buying an extra battery will make it more reliable..and you will be glad you did)
good luck..happy hunting..
oojoe