Capex of an inexpensive flexible wing like NPW

Indeed NPW is a power kite, and a power kite is more solicited than a static kite, and its wear can be expected as higher.

Yes, but scaling up leads to the requirement of thicker and stronger fabrics. It is the reason why I roughly evaluated for 20 euros/m². In fact that can be more for a crosswind use, given the high constraints during operation, comprising the wearing yo-yo phases.

Basically I think your message is relevant. Another advantage of a static system is the possibility of a higher elevation angle (above 50 or even 60 degrees against 30-35 degrees for a crosswind flight) and a safer use.

A turbine lifted by a kite could be both the simplest and most promising AWES as its Power to space use ratio could be more effective, but unfortunately its potential is very low.

Perhaps it can scale by being implemented in networked systems (in order to avoid collisions between unities), using the bumper car mode, but the low potential would remain, and also it is for another topic.