That is just so overpriced it's maddening. Many options that will do exactly the same thing for 1/2 the price. The buckles and clips on the harness are not necessary unless you have mobility issues with your shoulder(s). BPW's used to be made by hand in people's garages out of old ss plate or even street signs liberated from their poles.
The whole idea was too have a SIMPLE rig that would work in most any environment and not cost an arm and a leg.
A SS plate can be found for $100-125. There's $20 worth of hardware and $15 worth of webbing. I've got a 32lb HOG wing in like new condition I'd want $175 for plus shipping.
$300 with the soft plate HOG comfort harness and two steel buckle cam bands and 5lb weight pockets that could be moved to a steel plate in about 30 minutes if you've never done it before.
I could make the swap in half that time. You'd still be around half of that price for the Hollis.
Setting up a BPW is not hard and I have an 11 page essay on the style of rig with photos of how it should be adjusted.
At that price, what you are looking at is about 350 worth of materials, and the rest for the name, maybe getting it adjusted correctly, and not much else.