I've had trouble finding case studies of B2B development deals. My past experience includes lots of milestone-based development as a contracted solo dev.

Now, I'm bootstrapping (in stealth) a B2B service with 3 employees. The basic service exists. To continue funding, I can get VC investment, or I can get business customers to pay up-front development costs, to customize to their use case.

Let's say for a normal customer, the service costs $X / month. I want to write a deal with a business customer where they pay $Y up front, for us to build the service for their use case. Maybe in return, we discount their usage cost: * their cost is $ 0.5 * X per month for Y/X months, OR * their cost is $ 0.5 * X per month for (1.5 * Y/X) months (like a loan with interest), OR * their cost is $ 0.7 * X in perpetuity (permanent discount), OR * no discount at all, and we the cost to the customer as early access.

Is the long-term pricing model seat/usage based? Value based?

Consider how much you want/need to be charging customers in 3-5 years time and work backwards from there. Be open with early customers on these prices. Offer discounts (sometimes even permanent) against these target prices for early customers/design partners.

Pricing is something I struggle with too. I really need to figure out my pricing model and price point as it makes a difference to some deferred architecture decisions. I can't put the decision off much longer as I'm getting to the point where I need to make a decision.