I think what you really need to ask yourself is do you want to open ANY type of home-based business? I would talk to an accountant who specializes in small businesses to see what the ramifications are. How comfortable are you with debt in general? Your friend/rep should be able to give you a ballpark idea of the monthly payments. on a new machine. You can then determine if you can still make the payments during your learning curve, or in slow months.
Sounds like there's lots of quilting going on in your area. I would contact the other Long Arm quilters and your rep and see if someone would rent you time on their machine (after Christmas of course!). I'd try to see if I could do an entire small quilt. This should give you an idea of how long your learning curve will be.