That's a very conservative guess. My 18650 laser with copper heatsink and really good battery cost probably $190 (including things like goggles and thermal paste though).
Well its not a guess, i have made 3 445nm lasers all around or under 100$
i dont include goggles in the price of a build because you dont need a pair with every build they are a on time buy.
Thermal paste is adding an extra 5$.
And depending on your host you can use any old flash light or project box to a pure silver host.
The laser itself has a set range on its price too.
it seems the last component that could vary widely in price is your heatsink.
at 190 just seems like you paid alot.
where do you get the other 90$?
copper heatsinks are maybe 40$ max. maybe a bought driver for 30$ Battery and charging system takes the rest?
And as for what you said, you can't really use an lm317 driver in a flashlight host.... I HATE labbie hosts, your $100 price would make sense for a labbie. The cheapest handheld I could think of would be in a pen host, which would end up being around $100 probably.
very true but i happen to have fallen in love with these CTA Digital 9V NiMH (325mAh) Rechargeable Battery DB9V - B&H
now i know there the whole factor of 10 in time of the battery power but i charge the battery every night and never use the laser long enough to kill it.