Yes, these parts appear quite expensive for what they are, but they are pretty much the same price as any mount from elsewhere, and they position the GPS perfectly, with zero vibration.
The solutions that mount the GPS above the bike's TFT are nice in theory, but in practice, they vibrate too much for my liking. This bar mount puts the GPS in the eyeline with no issues, although it will not work well with a tank bag - if that's your thing.
Overall, I'm very satisfied with this purchase.