DTRs item are 1st quality that he harvests himself--individually tested by DTR and guaranteed --- worth the little bit extra
Not sure anywhere is going to be much less expensive---the market is what it is worldwide. I wold guess medium power 650nm red would be the least expensive.
There is a guy in Bulgaria sells 1W 450nm blue for $19 buy it now but has auctions going from $10 to $---makebe bid on one and get it for a low price. See:
1W 1000mW 445nm Blue Laser Diode to 18 5 6mm | eBay Maybe one of these used but working diodes
1W Blue Laser Diode to 18 5 6mm 445nm N | eBay
Only other choice would be search AliExpress :
Shop laser diode online - Buy laser diode for unbeatable low prices on AliExpress.com you can refine the seach as to color and power you want.
What is it you actually want at end of day--you can probably buy a complete hand held laser for the same price as a bare diode on AliExpress. Gearbest who offers LPF special on a lot of products has a whole page of blue, green, violet, and red Laser 301s for sale at currently $7.22 --is a give away price---- they all say less the 5mW but that is just for Customs purposes ---email them to find out the actual power if interested see
Laser 301 Best Deals + Free Shipping | GearBest.com
Several people here bought the 301's units--they were beyond great for the price. See reviews here
http://laserpointerforums.com/f52/gearbest-laser-301-high-power-405nm-blue-light-zoomable-laser-pen-92098.html
See this thread --guy got a nice 1400mW 450 blue for $47
http://laserpointerforums.com/f52/cheap-aliexpress-445nm-10000mw-93899.html
Also have a look in the IPF Buy, Sell, Trade sections--always some bargains there.
Something for nothing is unfortunately "out -of -stock" and "backordered" everywhere