I am all for saving money and DIY projects, but lights from dinotte and NR seem a decent value for what they provide. Turn-key lighting systems with reliable service records, a warranty, leading technology (if not cutting edge), and ease of use. They serve a purpose and help people who would rather not build a unit on their own or don't have the time. 800 lummens for $429 is still a pretty good price considering REI has the Trinew (489 lummens) for $399 + tax. ~300 more lummens for only $30 more.
As for people who want to strap on 4 flashlights onto the front of their bike, consider that people who buy a Dinotte or NR only have to plug in 1 battery to recharge, press 1 button to get light, don't have to find space to mount 4 lights, and don't have to bother aiming 4 lights. That has to be worth something right???