I got one for ~$700 with that (though Tourney, not Altus). The tradeoff however was power (it's 250w) and size (plus build quality, probably... also, no suspension or ignition) but it does work. I've tried an XP 2.0 so I do have some frame of reference, it still works for me.

I wonder if I'd like an even smaller bike (currently already 20" wheels, somewhat short wheelbase, 45lbs), though I might just want a lighter bike (which would cost more). Well I would wonder, but from what I've seen I'd need to buy something used (and it's more of a UK thing) to get a small (non-electric) bike for under $700. Sometimes just the frames for those cost over that. Also, searching for this size of bike is difficult (results give small motorized things (even w/bicycle), bike models, clown bikes (no gears)).