YOU pay that.

But firms often pay much lower.

For example:

https://www.interactivebrokers.com/en/index.php?f=1590&p=stocks2

$0.0005 per share with minimum of 0.35/transaction. If you trade directly with an exchange that drops much lower.

If you provide liquidity, you often get PAID to send orders. In this way, you only don't have slippage because you buy at the bid and sell at the ask (buy low, sell high, right? why would you do the opposite) The prices you execute at would exactly be at the price you set.

The largest costs are not transaction cost/slippage, it's the colocation and connections and data, upwards to tens of thousands of dollars per server per exchange, or the use of microwave data or building the towers themselves.