I once was dealing with a Gov't agency and they were required to do the bidding thing for projects such as this, but the office manager just wanted to get a few signs for interior offices replaced (new employee names) and he took a shortcut by providing the payment from a 'petty cash/incidental expenses' account credit card, and that job was done in a day.
I recall it was a $374.50 invoice, and we all went home happy.
This transom lettering decal appears to be around 2' x 3' size, and I would price it at $240 (including scraping off the old stuff, using some GooGone and Isopropyl, and squeegeeing the new decal up there, maybe the whole thing takes an hour, including design time, cutting, and on-site work).