Long term, It’s reasonable to for the RECEIVER to pay .25-.5% (25 to 50 basis points) in fees- ie the fees come out of the payment not on top of the payment.

Short term, it’s reasonable to pay up to 2% in fees.

For micro payments, higher percentages are acceptable but fees shouldn’t be more then 1 or 2 sats- with 1 sat fees being acceptable for payments as low as 1 sat, and “fee free” payments becoming accessible through liquidity provider networks where such micropayments help maintain a balanced network.