It's going to be really tough to find a quality e-MTB at those price points from a dealer. You could get into some direct sales brands like Commencal and find something, but a dealer is going to prioritize customers who bought from them when it comes time to service.

I'd also say that most stores aren't going to have much floor stock in on e-bikes or just higher end bikes in general. So it's probably unlikely you'll be able to actually see the bike you're interested in person. I know it seems crazy to spend that kind of money on a bike you haven't ridden, but I think we're just getting past some of the supply chain stuff to where dealers *may* actually have some floor stock, but it's not there yet.

A lot of people use the term "mountain bike" fairly generically to describe anything other than a road bike, so if you don't mind me asking, what type of riding does your son do? How old, and why an e-bike rather than an analog bike? At $3-5K, you'll find lots of good analog bikes available, especially towards the $5k range.