Solar cells for less than 1 USD per Watt

Nope. The thin film and nano solar cell manufactories are still statups and not producing anything suitable for unloading on eBay. They claim $0.50/watt when production starts, but that doesn't seem to be happening in the near future. Panels are currently about $5/watt. Reflector type arrays average about $3/watt.

First Solar claims $1/watt but that's hype:

The $1/watt is their manufacturing cost, not their sales price. Conventional initial sales price for a new tech product is about 5 times the mfg cost, putting them exactly the same as the other vendors.

Light reading:

Be sure to read this section on do it thyself and eBay vendors: