The retail channel is probably constrained as this seems mostly marketed toward businesses which might purchase along with a support contract. The retail market for these devices seems strictly supplementary to the main market (at least for Japanese brands).

Papyr is based on the same hardware as the Quaderno Gen 1. The hardware platform is licensed from a company called Linfiny. It's been rumored for a while that Quirklogic will release a Papyr based on the Gen 2 hardware, but it hasn't materialized yet. The Gen 2 hardware is worth it if you're doing a lot of handwriting because the Wacom digitizer is way, way better, but Papyr does have some additional software that could tip the scales in its direction.