I bought a extra cheap Brother a couple of years ago, because it came with a quilting foot. And I practiced free arm quilting on it. I am proficient, sort of, but it was always kind of a hassle for me, I have seen some of the things people on this board do and I am blown away.
That for me was the first step to see if I was going to want to quilt my quilts myself. And I was hooked, even if not great at it. I just got a Juki mid-arm (98Q) and a GMQ frame with the stitch regulator. People kept telling me I wouldn't want or need the regulator, but I like it. And I am so much better on the frame.
I would start small, because the big frames and machines are only more and more expensive. I think some people find that they really like piecing, but are happy to leave the quilting to someone else. Make sure what you want before you lay out the money.