There is a cost to everything, and not enjoying interactions is only one kind of cost – a soft and intangible one.
But there are also hard costs, in terms of serving the buyer.
Some people just keep asking for more, or keep throwing spanners in your works.
If you know your buyer, you can make a reasonable assessment of what that extra cost might be.
If you expect a lot of scope creep, it’s a 1. If you expect the gig to be reasonably effortless, it’s a 5.