I watched pj develop is his mini reefs and would endorse them. We had been doing small reefs for 10 yrs when his posts came along in the nano-reef.com forums and he was among a group doing something unique, a brand new niche of pico reefing not done as long term reefs, stilled reefs (noncirc)
How many reefs on this board now use zero movement? Sure they can be setup now that we have other paths to watch / copy but I can verify it was new science at the time, no longer was a quarter gallon reef good enough to break rules, but he stopped all movement shy of Brownian motion and uses the adaptivity of small tide pools to make a new reefing niche
He perfected and marketed the stilled reef technique so kudos pj.
In fair disclosure, the corals magazine edition of 2004 ish had Daniel Knopps quarter gallon stilled reefs in pics, open tops w daily topoffs but highly aquascaped=pro so I consider pjs work still different due to ease of care. weeks in between topoffs, these are partially sealed and stilled systems shown.
Value is simply what people are willing to pay, I for one find bio cubes grossly overpriced but that doesn't quell the market
Pj has a certain system that when I'm through buying replacement drone motors I'll pay him 150.00 for a tiny jar with matching lid and a mini external circulation setup he's already R and D'd into good working order (micro circ systems I dont have to hunt and source out have value to me)
Could I build one cheaper? Sure, but don't want to R and D for leaks or looks/combo, I'll pay for a custom version later on. Value is what people pay, I can count on three fingers of ten thousand posters the people who make money from vs throw it into the pico reef retail market. He's selling lots of these based on ease of use and no source or build work to get the same form factor look, once every few weeks topoff etc. good for beginners.
The parts he uses for his mini pump setup are not avail to me locally, and 150.00 is the most I'll pay to have one guaranteed no leak and ready, so that's value. This seems rather crazy to people who keep giant reefs no doubt.