the smallest fee is usually to sell orders or buy orders, if selling instant and instant buying will take a fee that is greater than the sell order or buy order
to trade with a profit of 1 $ -30 $ with a capital of 1btc it is not worth the capital and the risk, it would be better if I split your capital to trade a few coins for a more satisfying result without thinking about it
there is no zero fee market, while that is just a momentary promo