I'm not saying the idea is totally pointless, but the $500k needed regardless of the scale of the business seems a bit excessive. Maybe there should be a sliding scale, so that if your transaction volume is $10k, you need a bond for $10k, etc, up to a ceiling? That would at least make it possible to start out testing whether it works without dumping a huge amount of cash.
It does scale with transaction volume, but the floor is $500k. But it's explicitly payable via a surety bond, which works like insurance; applicants with good credit history might pay just a few thousand dollars to get one.
There is also a class of money transfer company ("A licensee that engages in receiving money for transmission") that only needs a $250k bond.
