well as a part supplier that would be me.
but as a full working unit self build around 70-100$
buy one pre built 150-225$
Also these lasers only lase above 200mw and can be driven as high as 1.2 (500 recommended)
they are but they cost more. (the 445nm lasers from casio are all worth the same no matter what power)
Before casio made them they were super expensive and hard to find but now you can get 200mw for the same price as a 1.2W(1,200mw)
due to they all use the same diode.
So if you want parts for a diy i can supply the diode.
Yup it will cost 100's
Sorry to say but the 445nm are being made by hobbyists.
There are a few company's but they rushed their product and made a bad product and they even cost more