I have decided to chime in with my own thoughts on this issue. Not that long ago when I worked at an LFS the most popular tank size we sold was a 125. We also sold many 120s and 180s but very few nanos. I visited the shop I used to work at today and they told me that they sell hardly any big tanks now. Now AIOs and 40 breeders are their best sellers.
For whatever reason people are getting smaller tanks. I believe it is a combination of better nano equipment and the increased price of large colonies. When the OP speaks of needing 6 lights keep in mind that this may be for people like me with 6ft tanks but now people who would have set up a 4 foot 120 years ago are now setting up a 40 breeder but with the same budget. I have to believe this is a large factor in why light prices have risen.
For whatever reason people are getting smaller tanks. I believe it is a combination of better nano equipment and the increased price of large colonies. When the OP speaks of needing 6 lights keep in mind that this may be for people like me with 6ft tanks but now people who would have set up a 4 foot 120 years ago are now setting up a 40 breeder but with the same budget. I have to believe this is a large factor in why light prices have risen.