PoC should have lower oil costs given the fact that if you get a bad draw, so to speak, you're automatically screwed. I can get all the way up to round 20 (level 40) but I generally don't bother because by round 18 (level 36) it can easily take 4+ tries just because of bad draws and the oil cost is too high to justify that when I'm already around Rank 15-25 and there's no reward for being top 10/20, just top 3 and then 0-1%

If anyone's wondering about my team, I have:
5*: Super Pershing (28), AMX-13 (27), T-44 (27), T-34 100 (25), T30 (25), Jagdtiger (19), WZ-111 (17)
4*: Tiger 1, M26 Pershing, Panther 1, SU-152 (all 33), Sherman Croc (32), Jagdpanzer and M18 Hellcat (31) and M8 Scott (27)

Yes, I did some whaling, sue me. You won't get much It's not nearly enough whaling to get top 3