I've got an old body man who gets $25, an old lineman who makes the same, 'helpers' or folks with no appreciable experience get $17 and work up from there. Start a guy at something livable and give clear goals for raises, which is impossible in the custom
sign world. In your case, you may set a goal of just a rectangular trimless letter that is both perfect and completed within XX hours, sacrifice a sheet to get enough parts for repeated attempts, and let them try once a month/ 6 months/ whatever seems to fit their progress. It's going to be challenging to bring in someone to do top notch work if you can't pay them enough...
This is outside of the LR metro area in AR, and I'm probably paying better than other folks in town, no necessarily LR, they'd be closer to $30 depending on if they're running a crane.