I've had a LONG run of possible buyers who exhibited every buying signal, knew my rates then dropped out just before the deal closed. Is it something in the air? It's never been like this before.
The most important thing is to determine who is the actual buyer(s). You need to reach them, and develop a relationship. A lot of times, the company initially reaches out with employees who are, at most, feasibility buyers (they can say no, but not yes). You want to spend as little time as possible with them—just enough time to convince them to arrange a meeting with the actual decision maker.
The reason is that the actual buyer is the one interested in the value of your product/service, and he/she isn't strictly focused on price. If you go through the sales process with non-buyers, they would then go to the buyer and accurately give the price, but they won't adequately convey your value.
So, you want to sell to the actual buyer, ask him questions to uncover the value he/she hopes to get from your product/service and, then, before submitted a proposal with price, reach a conceptual agreement over all the value they will receive and find out their range of budget.
Then, submit three options. Option 1 should be the lowest priced option, should be within their range and, ethically, it should solve the basic problem.
Then, your second and third options can offer more value, for higher fees.