Do you want a quilt, or a "quilt"? (I'm a quilter, both by hand and by machine... there is a difference between a quilt and a "quilt").
If you just want a store bought "quilt", go to JC Penney and get one when they are on sale. I think I paid about $25 for a simple, light weight "quilt" about 17 years ago when I got divorced, and it has held up well. "JC Penney Home Collection", part polyester, part cotton. (I haven't made a quilt for my own bed yet, so still using one of the cheap ones). Avoid Walmart stuff, I've heard those fall apart in a year or two. Mine has been washed regularly, has not worn or torn.
If you want a quilt, but don't want to pay a ton (they can take hundreds of hours to complete-- my hand quilted baby size quilt has over 100 hours into it), see if you can find one in a thrift store, estate sale, classified ad, senior center (we sell hand made quilts for a steal at ours, but they are only lap size and child size). Even better, join a group and make your own ;)
IMO, you're not going to find a high quality quilt in a retail store.