Personally, I would not consider spending several thousand dollars now and then a larger amount later. I make a lot of quilts and decided I wanted to invest in something that will see me through my quilting phase. I am 74 and did not want to make a large investment, thus, I chose the Bailey 13 inch machine and I am confident it will still be working hard for me when I am 80.
Among the factors a person needs to consider is whether or not you want to do quilts for other people. I made the decision up front that I would only do my own quilts since I make a lot of quilts for charities. When friends ask me to do theirs, I have invited them to bring their quilts to my house. Then I show them how to load the frame and run the machine. (Nothing hard about that!) and that way they realize how much time it takes to get the quilt finished.
Since the first of the year I have completed about 15 quilts. one was a large 90 X 110 and another 104 X 120 for my daughter. Then I made a number of Standard and Queen size and child size quilts. . I have the luxury of time to be able to spend on sewing. I have done this all my life and want to keep active and keepy my brain cells alive. My father is 102 and considering this factor, I hope to be making quilts into my 80's. And I believe my Bailey, like the old Singers, will be around for a long time. Everything else depends on how long I am around to continue quilting.