It happened to me recently, I'm kinda newbie on PMing, so I ask this to an experienced community.
A potential client contacted me through the guy (intermediary) who offered the job to me. But to define if I can do it, I need to do some pilot testing with the things that I've been asked to integrate. By doing this I could get more realistic budget, and time/work estimates.
The wisest thing I could think of is talking to the mediator to ask for the elements to do those tests, and then define if we can do this on time. It's actually doable, but depends on the team (and myself) having a time rate of understanding fast, so it could be affordable to the client. And by saying this of course it's clear I still didn't tell them my price.
Our team's usual market is web IT, and I'm asked to develop a desktop HHRR controller with some hardware control devices.
But doing this could lead to the client expecting of us to get to work, or at least give him hope of we will do that soon enough.
And last but not least; those tests require some hours of work by the team and myself, What do I do with those hours? Are they paid? Should I let it pass by putting from my pocket to see if I can take or not this project? What if the project is not worth taking and people has worked on its viability?