12 years ago they had their own sign making in house, I assume they still do.
If it's temp, then the vinyl print and plywood it would be mounted to would be less than $100. If it's any other material - fiberglass, or Aluminum - with a vinyl print on top, then it's permanent. Even then it would be less than $2000 for the sign.
Can anyone get back there and see how thick the sign is? If it's 1.5" or less, then it's probably temp. Aluminum and fiberglass start at 2" thick.