The C-Notes are still a bargain at that price!
There's about $80 worth of drivers in there, which is bonkers for a $100 kit that also includes crossover parts and MDF cabinets.
For comparison, the $130 Overnight Sensations kit contains about $55 worth of drivers. That's a good deal, and consistent with other DIY kits... and it illustrates what an outlier the C-Notes are.
(The reason why the C-Notes are so affordable is because Parts Express and Dayton share corporate ownership, so presumably they're about to source those Dayton drivers for next to nothing)
FYI there's an MTM (two woofers, one tweeter) version of the C-Notes coming in ~45 days for $100/speaker ($200/pair)