Here's where things currently stand in my research and frankly there is no good solution, so it seems:
USBank offers Single Point Essentials with ACH direct deposit features, for $27.95/mo + .35/transaction.
WellsFargo has Direct Pay for $10/mo plus .50/transaction for direct deposit to non-WF accounts; but this is *on top of * $6/mo for BillPay (waived if over $25K in accounts), and on top of monthly charges & minimums for the WF business checking account itself. Adds up to quite a full stack. I already have biz checking elsewhere.
Paypal doesn't do direct deposit but can at least do an electronic transfer for free for both sender & receiver if paying via linked bank account. Requires recipient to transfer the funds manually back to their bank, with a delay in releasing funds. Paypal also requires a small transaction fee if funding via credit card, as well as offering pricier merchant account options that still don't include direct deposit from what I can tell.
Dwolla charges .25/transaction, doesn't use credit cards, and requires both parties to join Dwolla. The money is held by them until you transfer it to your linked bank account, just like Paypal. Given the ubiquity of paypal, don't see an advantage here....
I already charge people recurring payments via API call to Braintree. Too bad I can't similarly credit people recurring credits, given that Braintree is purely linked to credit card and folks don't give their credit card numbers out. I suppose I could hack a reverse payment form that encrypts a trusted user-entered credit card and is only used to send them money at my expense, but yah, that's not likely. :-)