For many of us, especially those who produce a lot of charity quilts, we come to the point where paying someone else to finish our quilts just gets to be too expensive. That is the point where we begin to consider a home quilting system. The Mid-arm machines are much less expensive and can fit into smaller spaces. We learn to quilt our own quilts and can do them in a few hours, depending on how much quilting we do on them.
On the other hand, if you are making heirloom quilts that you know your family will cherish and hand down to other generations, it might pay to have the beautiful quilting done by a Professional.
But for me, and I suspect for others as well, we want to quilt them so we can have a quicker turnover and put them into service at various charities. This is a fun thing to do. Ask the others here who own the home quilting systems.