It does add some cost to have them linkable rather individual models with varying power, but it is quite small.
Having multiple panels of varying power will cost more in initial machining costs, which will in the end cost more than the smaller model that can link up to make bigger panels.
The way I'm doing it, it gives more options at less overall cost. People can choose what to get based on their needs and budget. Not everyone will be able to afford to spend $4000+ on lighting a 4x4, that's why there's a 50w version of the CXB. Still great efficiency. You can take 12 of them for 25% less cost and 200 extra watts, and make three 47"x7" panels and spread those 600w over a 4x4.
For those that can't afford that, they can look to the Veros. Still decent efficiency. Connect six of them in a 24" x 24" panel that makes 480w, or 8 of them in a 24" x 32" panel that makes 640w.
It really wouldn't be 16 individual panels over a 4x4, it'd be 4 panels, much more manageable.
There's something for everyone, mostly.