Whirlpool: ~5% once + mining fees (remixes free -> much higher privacy set over time) WabiSabi: 0% + mining fees JoinMarket: 0.01-0.03% per round (as Taker) + FULL transactions mining fees every time The "ridiculously low 0.001%" is not real and what is misleading here. You pay 0.01-0.03% and that repeatedly + the FULL miner fees, which is why JoinMarket usually ends up more expensive overall.

I believe the fee percentage is applied over the pool denomination. If you use let's say 0.05btc pool size, the fee would be 5% of 0.05, which is 0.0025btc. You will need to play with those pool sizes to see which one is more convenient for you. If the max amount of UTXOs is 20 per mix, and let's say you're mixing 0.1BTC, you use the 0.001btc pool size, it means you'll have to do 5 different mixes. Each mix is 5% of 0.001 (0.00005), in total for 5 mixes is a fixed 0.00025btc fee. In that case, your fee was 0.25% from your balance not 5%. Obviously if you don't know how to use whirlpool and you have 0.051btc, then you mix on 0.05 pool size, you'll end up fucking it up and finding out near 5% of your balance is gone. Depending in what do you want exactly you may find wasabi/join market/joinstr cheaper or whirlpool cheaper.