I am certainly glad I am in my area because I do this kind of work all the time. I live in a small metro area, and I have a reputation for design and quality work. The big union shops that do their own fabrication charge considerably more (I know because I owned and operated two of them over the last 30+ years). Sometimes I get beat on price by some of the smaller non-union shops, but my quality is usually heads-up above their efforts and I stand by my prices and quality.
As far as my shop model goes, outsourcing allows me to concentrate on sales and design without getting bogged down in production. To be honest, I have a small shop for light assembly, painting posts and such, vehicle graphics, hand lettering, a circular saw and a jig saw and a few saw-horses. A lot of my work requires final assembly, but a surprising number of jobs come in ready to install. I have two licensed, insured and, most importantly, experienced sub-contractors that do most of my installs (I do enjoy going out once in a while myself). I could easily run my business from my garage (I have), but having a shop makes it easier, and the small monthly expense is worth it.
I have a lot of experience, and know a lot of local craftsmen, all of whom are invaluable. I would not recommend my model for a beginner, but an experienced sign person that knows all the facets of the business could easily set up something along the lines of what I do. Eliminating overhead is the main objective, while still maintaining and in most cases improving quality. I can attest to the fact that the fabricated signs I get from my out-sourcing partners are at least as good and in most cases better than the ones we made. I know my costs went down when I started outsourcing digital printing. We never had a dimensional CAM router, but I have hand routed dozens of signs (with a plunge router and a v-bit - talk about tedious). I can get unfinished routed sign for about the same cost as it used to cost us to buy and inventory the wood and glue up the panels. Everything has changed, and even more so in the last 5 years, and I feel fortunate to not be encumbered by a large shop and be able to take advantage of a new way of doing business.
By the way, I quickly calculated the price of your sign at 18.5" x 42" @ $1546 (my time plus $742.00 production cost). A similar HDU sign with an internal steel frame routed and sandblasted would be around $1350. Installation would be $460.00 with permits. I can't speak to the art other than if the client had an existing logo the layout costs would be minimal.