Hydroponic tomatoes usually yield about 200 pounds per year per square yard. Of course, it's real dumb stupid to go hydroponic to grow herbs, traditionally you just suspend a series of pots with dirt in front of a window - if you don't have a cat - or use a pot on the windowsill with room for the cat to still doze if you do.

This cat aspect being pretty important here, I'm looking at their setups and your average cat will not be able to resist climbing and swing from those, which will, I assume, drastically effect gross yield.

Indoor gardening is not advised for pet owners or those with toddlers, especially setups that involve electrical pumps and lights, this looks like a project designed by a bunch of greenies with little gardening and DIY experience. A few pots with dirt on the sill, maybe some cords for vining plants like tomatoes, should do the trick for most people. Actually having a hanging but non hydroponic window garden can be created for about ten bucks a window tops, basically the cost of some empty soda bottles, seeds, potting soil and nylon cord.

I always want to hit amateurs who in an attempt to be green somehow manage to spend way more money for their yield then going to the store, it so horribly misses the point.