Ask HN: How to respond to a request for custom work with supershort description?

We sell our product hosted, and on a regular basis we get sales knocking on our door: a customer wants this-and-that report (followed by a 20-word description), how long will that take us, they need it fast?

In the past we tried to get more information, it never came, sales looked at us like: "this description looks pretty clear to me, what else do you need to know", we still estimated, and we ended up losing money, and/or the project went completely sideways.

Usually these things should take a few weeks at most, so they are small, but as a company we really can use the cash.

I always ask the programmer that is intended to do the actual work, but they come back with either no estimate, or with a far too high cover-my-ass estimate, which we cannot sell.

What's the best way to handle this?