The "high flux cost" is mostly because bottom line, it costs $5 for a chest. The price of flux (on the market) is a little lower because people have, 1) decided to 'eat the cost' and 2) have existing items that they gave up on.

I don't think it's the $5 cost that's the problem. Everything is relative. And relative to the SCRAP upgrades, items are EXTREMELY expensive (this is because the value of scrap has gone down). See, flux is more of a 'free market', while flux is fixed.

Another way to look at it might not be that flux is too expensive, but items are underpowered. The benefit to ANY item doesn't seem 'worth the cost' until you are level 40+ (whatever it is, it's high).