I agree. Live and learn. This was to be my first bona fide job since I left Idaho last summer, and I was eager to get started, eager to please, and far too trusting as it works out.
Giving some thought to contracts, maybe a good rule of thumb: If the client is large enough to have a business plan, they can well afford to accept a contract. I've developed a few personal (business template) sites for friends, and I wouldn't dream of asking for a contract in that situation.