I have not read all of the responses here but I know a lot of options have been offered. Here's my take. Since I am not a skilled free motion quilter at this point, if I were to make a quilt top that I wanted to be really special and really well done, I would send it out - especially if it were a large one.
It is possible that your wife will decide to make more quilts and smaller ones that lend themselves to a stitch in the ditch (SID) method that is much easier to do on a domestic sewing machine (DSM). Also, smaller quilts and projects might give her the opportunity to practice her free motion quilting (FMQ) in a less challenging arena.
Everyone winds up having their own preferences. I make a lot of charity quilts and I usually do SID on them with a little FMQ in the borders. That's for now. I hope to improve over time so that I can do larger and more challenging projects.
But, as several have mentioned, prices vary by your location and it would probably be advisable for your wife to find some quilt classes or a quilt guild where she can get some additional guidance.