>>I am not very experienced with this, but I would expect that you would have to do a lot of requirements gathering and design documents up front - how do you charge for these? What if you spend significant time completing these documents and have the client back out before any agreements?
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>>Requirement gathering is billable work. I always charge my clients my standard hourly rate for creating a specification. After they pay for it, they own it and if they like they can hire me to perform the work or they can hire anyone else they want to.
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>>FWIW, I never do fixed bid work. I always work on time and materials, but I am an experienced developer. I have a reasonable idea of how long a finite task will take. So I give my clients time estimates that they know are accurate to +/- 20%.
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>Thanks for the answer.

I work very much like Marsha. I sell the client on the idea of the flexibility of short cycles between their seeing what I'm doing as we tweak and design. I often have them log into my box on logmein so I can show them what I'm doing and get feedback. This could be as often as twice a day. When you do that they don't seem to have a problem with the hours as they can see results and see what gets accomplished and how. I tell them flatly that on a fixed price bid it is common practice to double or triple the hours just to protect -against the unforeseen and it is difficult -especially on a very large project - to make adjustments as business needs change. Doing a spec, going off to write code and coming back in six months the client can see an app that no longer meets the business need or which reflects and basic miscommunication, even with the written spec. Short cycles and adjustment based on client input can save them a lot of money.