@Mel6934 The additional service fees are to be used as a deduction on your taxes, not an increase.
And of course you can't leave your pricing the same if you are now paying the entire service fee. Just as before, the guest is essentially paying the service fee, it just isn't evident. It's just a marketing gimmick- the end total to the guest should be same, more or less, either way.
To use easy numbers, if your nightly rate was $100 before, and the guest then had a service fee of 15% tacked on, their total to pay is $115.
If you are paying the entire service fee, you need to raise your nightly price to $115. Guest still pays a total of $115, you still make $100.
Unless you use a channel manager, though, you can change back to the split fee system if you want to. It just won't apply to any pending reservations made under the host-pays-all option, only future bookings.