US$50 is a perfectly reasonable price. It's not good whatsoever if you have even a moderately popular site as you will below through the page view cap lickity split. But if you just have a simple business site which you want to make sure runs smoothly, then US$50/month for WP Engine seems like a great option.

I'd have no problem recommending it myself, but only for specific people who would make good use of it. For the average site owner, it would be hideously expensive since they'd need to pay a LOT more than US$50/month.