For every dollar those broad heads cost in U.S. dollars is close to $7.00 going to China. So for the $15.00 mentioned is close to $105.00 going to China with the currency exchange. Even if the same time was required to build the broad head here, at the hourly rate here those broad heads would be very costly.
Due to the high exchange rate, is the reason some of those countries can ship smaller items cheap and some items ship free.
As for the design of the mentioned broad head, if the point is steel and is screwed into an aluminum body, there is where the problem is if the point hits a very hard object. The aluminum will enlarge, making for a poor fit.
I have some of the Gunnison 3 blade broad heads which are fixed, so I realize there is a difference in design. The Gunnison has a steel point, screwed into an aluminum body. I recently shot through a broad head target where the steel point stuck into a piece of plywood I used for a back up. I managed to unscrew the arrow shaft, but wiggling the point to free it, the aluminum body expanded enough that the point would not tighten up. You can purchase this brand of broad head in Wal Mart.
Shooting the same brand of broad head into my newly acquired Rinehart Rhino Block XL target, the blades pushed back into the aluminum knurled nut. When pulling the arrow, one blade came out and remained in the target. These blades are replaceable by unscrewing the knurled nut and inserting each blade in a groove, then retightening the knurled nut.
All the best.