I bought a Gammill Vision 18-8 in November of last year. Yes, it is a lot of money and, yes, I could have paid off some bills with the money. However, I LOVE making quilts and I now LOVE my longarm. Since November, I have quilted as many quilts as I did in the 2 1/2 years prior on my DSM and I am able to easily quilt a lot more patterns than just a simple meander. I am still practicing on my tops, but hope to start quilting for others very soon. The first 100 - 120 quilts I do will pay for the machine. I work full-time, so it may take me a few years to quilt that many, but I can also do my own quilts at the same time. My plan is to use quilting to supplement my income once I retire. So I need to start practicing now...right???
If you are having trouble getting started, the Linda V. Taylor book mentioned above is excellent. Also look for her videos online. I have watched many videos online and also belong to several Yahoo quilting groups. There are Yahoo groups for most of the longarm brands as well as groups for people with different brands of longarms. I also am on the Machine Quilter's Resource (MQR) forum. I don't have a lot to contribute yet, and most of the work posted there is beyond my skills...so far, but I get a lot of information and ideas there.
All that said, only you and your family can decide if this is the wrong time for such a large purchase. However, if you just feel you aren't getting your money's worth from it, just get in there and get to quilting!