I'm retired. I develop FileMaker Pro databases pro bono as a hobby, serving almost exclusively small non-profit organizations, chronically strapped for cash, that couldn't conceivably afford my services if I were charging market rates. But a couple of them wanted to know, for some kind of accounting purpose, what my donated time was worth. Since I never bothered to keep track, I could barely give them a guess as to how many hours I'd put in, let alone what they were worth.
But that got me to wondering:
What do FileMaker Pro developers charge for their time?
Is it per hour or a fixed amount of money for a well-specified, limited task?
Do you just use a flat take-it-or-leave-it price, or do you dicker and negotiate?
Do you have written contracts or just handshake agreements?
Any other considerations I should know about?