Which Tier X Tanks are the Most F2P Friendly?

TLDR: best tanks at tier X that aren't huge credit sinks?

For starters I am not a strictly F2P player, I have spent money on the game in the past and am likely to spend more in the future. However I've noticed that I really don't like playing tanks that struggle to break even on credits. I loved playing the Kranvagn before the nerf and I still like it post nerf, but lately I just feel guilty for shooting gold all the time. Not because I sympathize with the poor souls trying to utilize their armor, but because of how many credits I feel I am wasting just to win a battle for fun. Ending the battle at a 40k deficit always feels bad, even if I absolutely dominated that game.

I also found that I really enjoy the gameplay at tier X. I'm not an amazing player by any means, but tier X requires so much more thought and strategy compared to lower tiers because everyone is playing not only with the most powerful tanks available in the game (mostly) but also at the highest average skill level, meaning every decision I make is a bit more impactful than usual.

So since I want to play at tier X but minimize the credit cost of doing so, I've been looking at tanks that have decent standard ammunition. Currently I'm working on the Strv 103-B (very close to getting this one, literally 200k xp away) and the Leopard 1 since they both have excellent pen and gun handling.

You guys got any additional suggestions or advice?

Thanks!