Our local bank handed me one for a farm equipment auction a few years back. It was not an unusual thing for them. It was for less money than we had on deposit, but they offered it for more - we just weren't willing to spend it.
Check other banks, in other words. If you don't have a relationship with them, be willing to put as much in that bank as the letter of credit, and maybe leave it a while. Maybe check credit unions, as well.