Just to be clear, it's pay-to-progress, not p2w. 99% of pvp happens in the arena, where everything is normalized and gear doesn't matter. As for pve progression, you need gold and mats to upgrade your gear. Your have weekly limits to how much gold/mats you can earn, but you can use gold to buy mats off the AH. Whales have no limit to progression, since they can both buy mats straight from the cash shop, and buy the cash shop crystals that they can sell to players for gold, and certain other items that they can sell on the AH. Gold is the only thing that limits your gear progression and if you want to swipe away you can cap your gearscore in like a day.
Seriously doubt Amazon's cash shop will be all that different from RU. The ENTIRE endgame is specifically designed around the gold cockblock.
I've played RU off and on since launch and I have 4 alt accounts just to earn gold from the weekly gold bags and using labor points to farm ore to sell. This allows me to make ~4x more than your average free player (not 5x cuz I don't do the dungeons that give gold, too much of a pain to pug.) And it's never enough. Plus, there's the skill books. The ones you want are rare and cost a shitload. Occasionally there are events where you can get a few stacks of your choice for free, and that drives the price down on those. But the main ones that everyone uses are gonna take you a lot of time and gold to acquire.
I love the combat, game has excellent graphics/sound/music. The rest of it is a steaming pile of shit with a credit card slot.