Not really; the issue is that you don't have a way to disclose how much the bug is worth without giving away the bug itself. You can kind of ask how much an exploit that gets a local user root access is worth, but that can give away enough to let them focus their own search.

In general, you have to rely on this being a repeated game - you and the pentester community at large submit lots of bugs to this company, and you rely on them to make it worth your time and talent. If they don't, you go test someone else's software. Reputation is everything.