There are actually two separate questions here: 1) How long will this project take? The answer to this question is called an estimate, and there is a huge bod

There are actually two separate questions here: 1) How long will this project take? The answer to this question is called an estimate, and there is a huge body of work about it. 2) Should I offer to do this project for a fixed-bid / quoted / whatever price? I think you've already assumed the answers to the second is "yes"; and perhaps you were right for the situation in front of you. Beware the "winner's curse", though: http://en.wikipedia.org/wiki/Winners_curse http://en.wikipedia.org/wiki/Winners_curse which will quite commonly occur in a fixed-bid situation where some of the bidders are inexperienced with fixed bidding. My nitpick, though, it that is unhelpful to call this fixed-bid price an "estimate". I wrote (and recorded a short video) about that a couple months ago: http://kylecordes.com/2010/estimates-and-promises http://kylecordes.com/2010/estimates-and-promises