Ellis is absolutely correct that if you are a big dog, doing heroic photography for multinational corporations, you need a sharp lawyer on permanent retainer. Furthermore, you must absolutely wallpaper the client with forms and binding written agreements. Big dogs routinely sell to MBAís who purchase photography for a living, know all the dirty tricks and need to be watched very carefully.
But the major point of my answer to you is focused on my read that you are an amateur contemplating his first commission for a small client. Which is more like the situation I was in: a two-man commercial studio in the New England Rust Belt servicing corporations with about one hundred employees.
The point is that the general public has absolutely no idea what LF photography costs to produce. Just add up the price of a box of 4x5 film, a gallon each of developer, stop and fixer. Add your cost for a box of 16x20 paper with all the chemicals. Then tack on your total time, from loading holders and mixing chemicals, through shooting, processing, mounting, spotting, framing, to final delivery of the prints. Even billed at what McDonalds pays the french-fry maker, the combined total has got to reach a thousand dollars.
Present that kind of bill to a business owner and he will go into cardiac arrest. I guarantee you he was thinking more like 1/36th the cost of a roll of 35mm film and processing at Wal-Mart. And it doesnít make sense to hire a five-thousand-dollar-a day law firm to chase him for the money. He doesnít have it. And you canít afford the lawyer.
Andre had the best idea. Trade him a dinner for two for each print. And collect as you go. Donít let the bill pile up.