Then as for the transaction fee, it's actually another problem when doing business with it, especially when it has gone high, because you will be asking yourself how much you want to gain that you will be paying such a huge amount as transaction fee when it transaction fee has gone high
As the merchant, it is your customers that have to worry more about tx fees, because they cover the fees when they are spending in your store and you only have to cover fees when you want to liquidate your BTC for fiat.
The question you should ask yourself is how many % of your customers pay with BTC, if the number is not much, you can then liquidate BTC only on a mothly basis, that way you'll be lucky enough to carry out your tx when the mempool is free and you will have enough fiat to take care of your business without being in a hurry to sell off your BTC. Now if most of your clients pay with BTC, which is unlikely, use a payment processor.