Earlier quoted context omitted.
An intermediary like the mob, perhaps?
Do mobs do this? No, I meant a legitimate intermediary. If builders get to overcommit and then cancel on their customers, why shouldn't a customer be able to do it too? The intermediary would just offer a service of doing that for you - booking multiple companies for your construction project, waiting until the last second, and cancelling all but one.
Why couldn't they? I'd imagine the only problem is it is an ineffectual strategy for a client. There is a lot of money involved, people are already doing everything they can think of to get the lowest price.
It is absolutely a dick move to lead someone on, but in the grand scheme of things a minor problem. Construction is a mess of problems.