Decent BUIS for less money?

[Frontier Gear]

I saw these on the shelf at my buddies shop in Spokane yesterday. I asked him how they were holding up. He said that they have installed them on a number of guns so far including a full auto 45ACP. I guess that the 45ACP is a real shaker and mover when in full auto. He says that it hurts his hand to shoot it. But the sights are still holding up. They stay put (either up or down) and they are still sighted in. Mind you, he doesn't really use the sights when doing a full auto mag dump... These are made out of steel instead of aluminum so that could be helping them. I may try a set out, just to see for myself.

https://www.amazon.com/Trinity-Force-Sig...B00MJKOK28