This is all great advice! Don, your point about travel is a good one. We're thinking of asking for $450 and settling for $400, but in the several email between the bride and me, no one has mentioned price yet- Hunt worked for years selling his artwork, and says, "Whoever mentions money first, loses." So I'm holding out for as long as I can, until and unless it looks as though the bride assumes we're doing it for free!
Be assured there will be a contract and a "payment in full one month before the event" or some such. As we have learned to our sorrow.