Most of us who machine quilt do not have long arm quilting machines. I use my trusty Bernina 1230 to machine quilt. I would suggest setting aside money from a longarm later on, in case you get that far into quilting that you really want one. Some quilters who buy longarm machines are too intimidated to use them. Plus, when you buy a longarm, you really want to immediately taking training and classes and *use* it to get up to speed. Buying it and then not having the time to use it will be unhelpful.
Edit: A rule-of-thumb is to research longarm machines and frames for at least a year before purchasing. Also try out as many brands as you can at quilt shows before making a decision. Most quilters have definite preferences in longarm machines, just as they do for domestic sewing machines and cars!