Yo, I used to work in the credit card industry, so let's talk credit card fees and transaction rates!
patreon.zendesk.com/hc/en-us/artic…
That's for EVERY single pledge you make. So if you make 10 separate $1.00 pledges in a month, that's $3.50. Plus $2.90 if we're including the 2.9%. that's 2.9%+0.35 per transaction. So ~$6.40 you'll be charged on top of $10 in pledges.
As a patron, if I pledge $1-5 to many different creators, i usually just see 1 lump sum come out of my cc bill.
In merchant industry, that 1 lump sum is charged the transaction fee once.