It's expensive. Really expensive. I remember a major bank calling me and my buddy's 2-man consultancy team and telling me they had spent a small fortune on whatever the top-level access to MS developers is, to get some outdated MS COM component to interface with .NET, and MS had failed.
(We charged ~$20K and estimated two weeks. We had it working in two hours.)
I gotta ask, did you spend a week sucking your teeth after that, or did you hand it to them and say "hey, you're paying for expertise and we got it to you faster than we estimated"?
The correct way is the send the customer the almost-final version and wait for the bug report. This way you show how quickly you can tackle the problem but don't make the task look too easy.
Yeah, exactly a week. There was no way we could send it immediately, despite the fact it was ethically dubious to hold back.
This sounds pretty challenging. Could you please elaborate on your experience?
This was back in 2004 (?), so too long ago to remember the details. I remember the phone call though because the chap that called us said he been told we never used the word "impossible."