If I had $15,000 or so I would get an Innova with lightning stitch. However, what I have started with is a used Voyager 17/Stretch Hinterberg setup that I purchased from a local quilt guild member for $3,000 (she upgraded to a used $7,500 Nolting setup). My Voyager/Hinty is a wonderful entry-level frame quilting setup.
There are advantages to purchasing used, especially if you can buy locally. Aside from lower cost, a lot of the things you need are already in place -- such as leaders. Often the seller can offer you help getting started. Also, a used system at lower cost is simply not as intimidating to a beginner. On the homequiltingsystems group (a great group to join at groups.yahoo.com ) I have seen a number of posts from people who bought an expensive new quilting frame setup and then let it sit for a year trying to work up the courage to get started!
The rule-of-thumb at the homequiltingsystems group is to research and test machines for a year before making a purchase.