Your kidding??? $20 is an amazing deal. That's what I learned to sew on as a kid in my grandmothers laundry. It could sew denim, canvas, leather, plastic sheeting, you name it. I have a Chinese copy of that machine that is a dedicated "ruffler" and pleat machine and it's 'almost' as good.
Those old machines were built for daily use as a necessity, not a hobby, and were tough as tanks. Can't go wrong.