Been working with a prospect for 9 months. I quoted them a $10,000 retainer instead of a $10,000 starting fee for a poc (retainer means it would be drawn down from as other fees are accrued, so it isn't revenue). The other fees amount to around $20,000 for a poc, but this mistake would be a big hit.

It's possible we make up the loss if the poc goes well and turns into a full engagement. I have a very good relationship with the prospect. Pricing has been circulated and approved by the decision maker. Pricing was sent in the form of a estimated pricing one-pager. No official paperwork signed. The next step is agreeing to a SOW, then contract.

Is it worth communicating the misunderstanding and trying to work out a base fee instead of a retainer, or do we suck it up? It's for an early stage startup, and this would be a great strategic first customer. My sales mentors giving me wildly different advice (from suck it up to give them a call to just include it in the formal document I'll be sending soon).