RV people might get a kick out of this.
In the real world I'm a used car/commercial truck dealer. My old sign dated from 1989, and per the technology of the day was made of MDO plywood with hand-painted faces. Really, really needed an update.
These days computer cut vinyl dominates the sign business. You can get it cut and applied at a very reasonable price; plenty of competition. The cost only goes crazy when you need to hire an outdoor sign company for fabrication and field installation.
We build airplanes; nothing hard about a sign. I designed a new "shell" to encapsulate the old wooden sign, in 0.040" white factory enameled aluminum with bent and formed internal ribs. It just floats on the old wood and steel structure (no expansion/contraction issues). Any seam or rib that was under vinyl got dimples and flush rivets. Each face weighed less than 20 lbs.
Anyway, fabricated the faces, took them to the vinyl shop for lettering, then assembled the shell over the old sign on site. The whole thing came in less than $1000 for a double face 8x5, installed. See, it really can pay to have some sheet metal experience.
Anybody wanna buy a low mileage bucket truck? <g>

Shot at 2007-06-27