I've found some really cheap relatively good ones here
. The web site is really crappy and you have to call/email them to order, but I think this is a good option.
As far as ebay, I'll check it out right now.
I'm liking that 40 pack you linked to, if I use two of them series I can get ~8V@450mA. Pretty good.
I'll keep looking...
I went with Plastecs (the crappy website one) and I must say their actual service is great. Custom made solar panels on the cheap.