Strictly speaking, being on the GSA schedule and being able to offer products/services for sale to the federal government requires that you not sell that product/service anywhere else for less than that GSA price.
This is actually one of the reasons that doing business with the government is less lucrative than the commercial industry (for products and services which are comparable, many are things only sold to the government, so there is no hesitation about pricing them through the roof).
As you can imagine, one of the ways that duplicitous federal contractors get around the idea of having to sell to the government for less than their normal prices is to structure their products/services as different (and therefore not apples to apples comparable).
I still would bet that the price that they charge Goldman Sachs (just as an example, I don't actually know which investment banks are using their product) is higher than what they charge for any individual government client.
Also, I think it's probably worth noting that the maximum addressable customer base for their products for federal agencies is way smaller than the equivalent number of financial customers. There's really only a handful of agencies that have this capability (I'd guess more than a handful, but probably less than a dozen).
