$1 is not market.

I've signed up for or seen the contracts for several payment processors across several companies. Rack rate for ACH debit starts at $0.25/trx and goes down to sub-penny at scale. Returns can be high though ($2 per, going down as well).

Edited to add: that's not a defense, I *loathe* ACH. It's a negative-reporting system which is such a pain to deal with.

My understanding is that sameday ACH does not cost extra (from a network perspective) than regular ACH, it's just that some shitty banks apparently like to charge extra for it.