I think you and the OP might be interpreting the question differently. I didn't see it as to why equipment would cost more than the individual diodes, drivers, acrylic- I think the OP understands the cost of sales, R&D, delivery, importation tarifs, general overhead, etc. Instead, I saw it as a question as to why many of the bigger LED manufacturers are choosing to sell the equivalent of macbook pros and fewer big name led manufacturers are selling the equivalent of dells/lenovos? I think it's a fair point- for every NYOS or Royal Exlclusive Skimmer out there, there is a Reef Octopus so there's a pretty nice gradient of price points. While there are a few mid level LED lights, I mostly see lights targeted to the luxury market on one end and black boxes on the other end. You don't see a ton of manufacturers making the equivalent of black boxes (no frills) with reputable drivers/leds.
This might just be a question of perception, but if I wanted to buy a return pump, I could buy anything from a jebao to a tunze with various big name companies in between. I could choose to spend a bit extra and get a DC or wifi enabled pump, choose my pump based on wattage, size, or noise. Most pumps would deliver equivalent performance, it's what I found to be important to my particular need and I would pay accordingly for the perks or lackthereof. I don't see that same diversity with LED lights.