Just watching people at shows long arm makes my back hurt so I'll go at your question from the $$ viewpoint which seems one of your focus points in asking for input.
Getting my quilts quilted runs about 260-275.00 (queen+) At $12.500.00 if my math is right I can get better than 40 quilts done, and mine are always double sided, which is 80+ tops.
Setting aside you may be rich as Croesus, $12,500.00 is a lot of money. Is your house paid for, your cars, do you have zero consumer debt? Are your kid's college funds funded? your Roth or IRA? Is there house maintenance going wanting, roof/plumbing/electrical/windows?
At the very least do you have the funds saved up? If not have you factored in the interest over time into your mental cost total?
Love your avatar quilt, and best wishes on the journey. I've often found the journey is the most part of the fun, finally getting is a bit of a letdown.