I've got the same question. I've been looking at the cheap-o machines at the big box retailers and all I can tell is that:
1) The more stitches the machine will make, the higher the price. Most of my stitching will be straight line. I don't need a machine that will do a flower pattern stitch.
2) Really cheap ones (sub-$50) seem to be "light duty" making me wonder about whether they can stitch through thick poly webbing.
So what do I need to stitch rip-stop nylon and webbing? I realize name brand recommendations create fights, but I am looking at Brother (TM) and Singer (TM) because I have access to them and they're cheap. I am open to others as long as I can keep it under $120. Model number recommendations are great, too.
Ramblinrev, thanks for your insights. I'll read more on your post later. You've got a lot of info I want to read through! Quality is less important than brand, I agree. But price is as important to me as quality (in other words, I'd rather have a machine that will do a good straight line stitch that costs $100 over a machine that does several patterns equally well and costs $300).