Y'know, asking folks to pay for a game isn't all that bad. Asking folks to pay 1000 kreds = $100 real world for $125,000 in-game that buys you ONE GUN? That's a bit ridiculous. Five bucks to unlock all content and double your energy recharge, sure. Ten or twelve, maybe. $100 to get a partial unlock of premium content? Really?
The matching system does need some readjustment; two level 3s against one level 6 still don't stand a chance, neither does 4 level 1s and 2s against three level 3s or 4s.
Gold and oil should be a bit more common as drops from Marauders. I'm only level 4 at the moment, so I don't know if this gets better as time goes on. I understand you want to benefit the people who pay for the game, that's fine, you have every right to. However, it's a bit annoying when you run out of oil and have no way to replace it and then suffer a 20% penalty to EVERYTHING. Also kinda sucks that you look at getting 5 gold per day and the measly 2% boost prototypes require 150 gold. That's a month of play time right there. Other than that, great game! 4/5 so far, easily 5/5.