Of course you'll want to check measurements and make sure your font matches up perfectly -- standard stuff. Lighting seems to be salvageable, but if not, make sure you source the same LEDs. My biggest concern would be making sure the new faces are the same white (or brightness) as the old ones. Acrylic? Polycarb? Thickness? You might even check the UL Listing # and do a reverse search to see who fabricated it. You might get lucky and be able to source it from the original trade supplier. I've done that a few times with
Sign Fab.
And for "shoot from the hip" pricing, you can probably expect a resale price of around $20-25 per inch of letter height. (I haven't used that pricing model in a long time, so the numbers could be off)