Not sure why you think R3E uses the rFactor (ISI) engine. Most of the point of R3E being a completely separate and new title was being able to have its own engine.
In terms of the pricing, I actually find the pricing to be better than most current sim racing titles. iRacing's pricing model is ludicrously expensive. I've easily spent more than 3 times the money in iRacing for about the same total amount of content. Stock Car Extreme is only $30, but it's also based on the original (outdated) rFactor engine and doesn't have as much content as R3E. rFactor 2 can be had for around $90 with a permanent multiplayer license, but it also lacks a lot of content and many mods are not 'up to snuff'. Similarly Assetto Corsa is around $50 (Plus the $15 dream pack or $55 for both) but still doesn't have as much content, though it does have a strong modding community. When you look at the other options, realistically R3E's pricing model is right in line with, or better than, the competition. It will become tougher for newer players to make the initial investment as more tracks get added, and maybe that can be adjusted at a later point, but in terms of price to content ratio R3E is doing pretty well compared to its competitors.
I definitely agree about the multiplayer servers. At EU peak times you can generally find 1 or 2 servers with enough people to get a good race, but as soon as it rolls to peak US times the servers empty almost completely. Dedicated servers should alleviate some of this, to an extent, but mostly it seems people don't want to stay around in servers long enough to get the US community rolling or there aren't enough US players.