My primary processor is a standard merchant account provider and I pay interchange plus 0.04%. Interchange is the set of fees Visa and MasterCard charge to the processor, and starts around 1.8% + $0.10 for card-not-present transactions.
I also accept PayPal as there's a large number of countries where credit cards are not easy to come by and fund, but PayPal is readily available.
Both the merchant account (1.84%+ + $0.10) and PayPal (2.2% + $0.30) are significantly cheaper than Stripe (2.9% + $0.30) which someone recommended last time you asked this two days ago.
PayPal actually starts at 2.9% + $0.30 and charges a variety of add-on fees which you didn't include in your assessment: $30 per month if you want to design and host your own checkout pages, 1% cross-border surcharge if you want to accept payments from another country, 3.5% transaction fee when your customers pay with American Express, $0.30 per uncaptured authorization, a fixed fee portion of the original transaction fee when you issue a refund ($0.30 for domestic payments).
They do offer volume discounts, which is why you're at a 2.2% rate, and Stripe also offers volume discounts to businesses on track to do $1MM per year.
I'm not sure what your current processor and merchant account provider are, but we often do similar assessments against their add-on fees and come out to be less expensive.
The only fixed fee my current merchant provider charges is $5/month, and I pay a $99/year fee to a PCI scanning service. The merchant account space isn't resting on its laurels with startups like yours moving in; there's dozens that have moved to simpler pricing and eliminated bullshit fees to remain competitive.
Anyone accepting mostly domestic transactions with a monthly volume between a few thousand and $80,000 is probably going to save at least $30/month by choosing PayPal over Stripe, so the monthly charge isn't really a barrier even for their Pro service. Unless they go through one of your partner integrations like Shopify where you seem willing to offer the discounted rates without a minimum volume. I've set up a few people on that, it's a good deal for little shops.
Stripe is a blessinq!
PS : did you read Authority from Nathan Barry ?