Creating and selling a customer made program.

[JPicasso_00]

Get it in writing. The original scope of the job,
and what changes will cost. Then, arrange for incremental payoffs, when you hit certain milestones, 1/3 down, 1/3 when data gathering is running and 1/3 when reports are done/finished.

like that.

Joe Blow isn't making that kind of cash these days. Unless we're talking about a different kind of 'job'.