A couple of people have asked me for more details on the cheap pixel strings I picked up this weekend, here’s a picture of the box, the importer is in Essex, UK. I should think that the price I got them for was a clearance special though.
GBP £3.33 (US$5.50) for 15 pixels = GBP £0.22 (US$0.37) per pixel, with no shipping. A great price!
For comparison, the recent batch of cheap ‘promotionally priced’ ones from Ray Wu on AliExpress have been in the neighborhood of US$20 (GBP £12.30) for 50 pixels, giving a per-pixel price of US$0.40 (GBP £0.25). That price includes shipping, but you have to buy something like 500 pixels (ten strings) to get that price.
Looks like you found a real deal!
Were these battery powered, or mains? Looks like mains, which means for your money you also get a “free” power supply, too?
That’s right, each one has a 5V/1000ma power supply, so plenty to add to my box of wall warts. And I am going to re-use the control boxes, they are big enough to fit an Arduino Mini and a bit of supporting circuitry too.
Man I hope we can find something like this here in the us.
I got lucky with power supplies! It seems that the guy who works for virgin broadband seems to replace the hubs more than the power supplies. I acquired from a box in the street 30 unboxed 12v dc 2 amp net gear power supplies! For free! 
Kelvin, my luck normally works the other way, I’ve had to replace my Virgin Superhub power supply twice due to failures! Did it myself, a lot easier than getting an appointment for an engineer to come round and plug a new one in