The reason I am considering "harvesting" is driven by price and convenience. By the time you price up the delivered cost of two Luxeon III Star units, the reflector & lens, and aluminum forward shell, you are pretty close to the Sams Club asking price of $29. And they throw in 6 batteries to boot!

The reason I am looking at using a pair is to fashion the final pattern. I could 'tune' one for wide, and one for narrow, place two side by side for wider spread, or stage them near/distance. Not sure what will be best for casual road riding. But two give me the option to play with arrangements.