I'd say it depends on what stage you are in your progression as a gunbuilder. Early on, all paid work is good work.
Chances to build and get paid for it are sort of like bow wood, or gun blanks, etc. If you are a bowyer and have a stack of good bow wood, premium osage, straight, wide rings, seasoned 4 years, no knots, as well as some prime black locust, same deal, and some incredible hop hornbeam staves, and a pile of long moose sinew all processed, and somebody offers you a decent ash stave, you pass. If you can't find a decent bow stave to save yourself, and somebody offers you that same ash stave, you jump on it. Same might be true for gun blanks. If there was a shortage of thick blanks and all you could find was 1 and 1/2" wide hard maple, mighty curly, but you make early guns, then a plain jane piece of hard maple 2.5" wide would excite your interest. Same with building guns. If customers with deep wallets are lined up and you have a 3 year wait, you can pick and choose what you want to build and do it on your calendar, at your pricing.
If you are early in your career (anybody, not necessarily DaveG, who may be a high end builder, just don't know) and want to build guns and get established you need to be building and getting them out there. Consider yourself an apprentice early in your career, getting fed and clothed and learning the craft, nothing more. Go with the best offer you can get. And as you get better and more well known, your work will start commanding prices, and folks will wait for your work gladly. We could name some builders here on the forum who would be getting $1500-$2000 for well-built plain guns or $1800-$2400 for well decorated guns a few years ago but whose work now commands some serious dinero.