Any of the suppliers from China on Ebay. I recently got one for $4.50 with free shipping. 10-day delivery time to rural midwest USA (your time will vary by supplier). Though mine seems brighter than 5mw, more like 10-20mw. (Most of the dealers even include package-tracking now too, in conjunction with USPS's tracking system, their tracking numbers work with USPS as well as their own system.)
I order lots of things from the China and Hong Kong sellers now. They've been very very reliable. Why pay a re-seller in the USA when they get them from the very same place? The Chinese dealers seem to value honor more than money, like it's a contest to see who can get the most 5-star ratings, while undercutting the prices of all others to do so. Quite frankly, I don't know how they manage to sell and ship things as inexpensive as they do. Ordered 2 lasers a few years back, one didn't work quite right. No problem, they sent a new one and didn't even want the old one back (I eventually managed to fix that one). Honor and trust, something missing from the market-place everywhere but there these days it seems. Not had even ONE bad purchase from there yet, and I've bought over a hundred odds 'n ends from those sellers. Digital measuring calipers ($3.50! couldn't believe it, accurate to .01mm across its whole travel, every time), Illuminated-reticle zoom rifle scope $19.50 (works great!) the exact same model (from stamped in number) as sold by Bushnell for $79-99 (it's where they get theirs), etc. etc.
