Thorlabs.com - HL63133DG 637 nm, 170 mW, Ø5.6, G Pin Code, Opnext Laser Diode
$380 for 170mW. Ok. If you think thats a good price I won't argue.
I may be power hungry and enjoy lasers with higher power output ie: mw to $ ratio, but I know some guys enjoy centain wavelengths like to 473 blue...