Scoping tells you what you are actually buying. The BAFO is where that has to show up in the price.
In the previous note I argued for engaging the preferred SI on a defined scoping exercise, with a capped fee and clear outputs, before the implementation appointment is made. That work tests assumptions, settles the delivery approach and exposes what the client has to provide.
The best and final offer (BAFO) is the last round before appointment. It is where all of that is supposed to land.
But a BAFO is usually run as a price conversation, so a price is what comes back. Scoping will have changed what both parties know about the data, the integrations and how much testing the client is expected to run. The assumptions and exclusions in the original proposal were written before any of that was known, and they need to be revised before the BAFO can be stated.
That order also decides whether the pricing model holds. A fixed price resting on untested assumptions carries contingency you can't see. Time and materials on the same footing moves that uncertainty to the client, where it tends to surface as resourcing nobody costed.
So it's worth asking what has changed since the original proposal, which assumptions are now resolved, what the client must provide, which third parties are required, and which of those commitments carry into the SOW.
Otherwise the number changes and the risk doesn't.