Dunno about $30. I'd shy away from a $30 quadrail. Probably make of pot metal (weak) and heavy. Of all the ones I've handled I really like the Daniel Defense Lite. Its really light and nice to hold, BUT very expensive and hard to find.
Assumption is the mother of all ****ups.
Know what you know, Know what you don't know. -Paul Pedzolt
"Jack of all trades, master of none, though oftentimes better than master of one" -Mynshul