When deciding on a payment gateway/processor, here are some recommendations based on monthly your sales.
Best payment processor if you’re processing under $10K/month
With low processing volumes (under $10K/month) your costs will be largely dominated by fixed fees. That’s why you want to avoid any processors that charge a monthly fee.
You also want to avoid long approval periods, contracts and confusing pricing plans.
Fixed fees, quick setup and no commitment will give you peace of mind when starting your e-comm business.
Best payment processor if your processing between $10-100K/month
When processing between $10-100K monthly, the fixed monthly fee becomes less of a factor. At this stage, it makes sense to throw in Bambora Blended plan into the mix (2.8% + $0.3 per transaction and $25 monthly fee).
Both Stripe and PayPal allow you to negotiate rates at higher volumes.
On the other side, Bambora requires you to process at least $5 million annually to be eligible for lower rates (Interchange Plus), which is just one more thing to consider.
Best payment processor if your processing over $100K/month
Once you exceed $100K per month, Bambora (Interchange Plus) and Moneris are your best bet.
The rates will largely depend on your yearly volume and your overall processing cost on the ability to negotiate and waive unnecessary fees.
At this point the monthly fees are barely noticeable, so you can opt-in for contracts with these two companies and try to reduce your rates to a minimum.