What is the best way to facilitate payouts to user bank accounts?
After checking with my local bank wire-transfers are $25 each and can't be triggered programmatically. Where else should I explore for the ability to do this?
You should look at ACH or EFT transfers. Someone like paymentsgateway.net has a programmatic interface for transferring funds from your bank account to the users bank account. There are many interfaces to ACH it just takes some looking.
Edit: Wire transfers are typically for larger amounts of money.
Get a bank that can deal with that for a decent price. That simple.