The percentage is everything here
On a $3,000 invoice, a 0.3% difference in rate is $9 — more than a month of terminal rental. Fixed fees barely register; the percentage dominates.
That inverts the usual advice. Chasing a free terminal while accepting a worse rate is a bad trade at this invoice size, and it is the deal most often offered.
Commercial cards cost more, and your customers use them
Trade customers pay with business and corporate cards far more often than consumers do, and those carry materially higher interchange. A blended rate quoted on an assumed consumer mix will not survive contact with your actual card mix.
Worth having your real mix quoted rather than a standard assumption.
Deposits taken over the phone
A deposit taken by phone is card-not-present, priced higher, and carries the fraud risk on you rather than the terminal. If a meaningful share of your work starts that way, it needs quoting as its own line rather than being folded into a terminal rate.