Don't quit!!! You ask "What do you really need to quilt?" My answer? A sissors, a needle & some thread, and some fabric. That's how our grandmothers & great grandmothers did it! They didn't have all the fancy gadgets we have now. They didn't have unlimited access to fabrics. Many of their quilts were pieced from old clothing. I would suggest pausing for a day or two to read one or two books from the Elm Creek series by Jennifer Chiaverini. You can borrow these for free from the library. One book in particular pops to mind - The Quilter's Homecoming - really sheds light on how these women were able to create quilts out of virtually nothing.
Fabric these days is so plentiful. Check out your local Freecycle group. Check out the dollar bin at the local thrift store. Some of the coolest fabrics and buttons I've ever found come from discarded garments. I rarely donate garments anymore because most of them end up chopped and in my fabric stash.
When family members ask you what you want for a gift, tell them "Quilt Batting" or fabric for quilt backings. IMHO, this is by far the costliest part of finishing a quilt (aside from sending it to a long arm!) Or, you could 'quilt as you go' which would allow you to work in smaller sections and utilize your machine more, and work with small pieces of backing - important if you just can't shell out a hundred bucks for a continual piece of backing.
One more thought - if you are quilting as you go, consider used sheets and blankets in the thrift store for both batting and backing. I know a lady that uses nothing but laundered old blankets as batting because a) it's all she can afford b) the quilts end up really warm, and c) she donates all the quilts and the recipients don't really care that she's not using an expensive high end batting.