That's what I thought. If we batch made 100 at my engineering company we'd still be charging about £40 a pair just barely covering costs, CNC setup, materials and wages. Then the middle man would add his 50-100% and charge £60-£80 for them. So for £15.88 delivered it's absurdly cheap for very impressive decent levers.
I work in an engineering shop in the pharmaceutical industry and costed a pair to be made as an experiment in our place, CAD drawing, CAM program, tooling setup, materials, time, anodising..... £120.... each............... Although, that is for a one-off pair.