OK, I just have to ask. I've never seen any kind of gas block with that low a price. How can they do that?
The YHM 9383 gas block has an MSRP of $22 which utilizes set screws as well but isn't adjustable. That's the cheapest gas block I am aware of, but I haven't searched extensively for it either.
The Kies adj gas block is nearly identicle in size to the YHM lo pro, and looks to be really similar as well to the Sadlak as well.