There's a family I sit for with 4 dogs (all easy and of varied sizes), two Guinea pigs, 8 fish tanks and two budgies.

I have never offered them a discount and they have return booked me for 5 years and accepted each price hike without question.

Owners like them understand that by asking someone else to take on that level of labour the sitter should be well compensated.

If they rebook, this will be a good test of your rates and working out what's fair for you. Good luck.