Even if I bought my Pana about two months ago, I guess it's a 2012 model, not '13. The glasses I mentioned that came with it seem to be the latest type, with CR2025 batteries.
About where to buy my stuff, in live in Brazil and Amazon either does not ship here some articles or charges you a lot for shipping. Buying from eBay has proven cheaper and with very little counterfeit risks, if you know what to buy.
About the Samy glasses, the 5100 seem to supersede the 4100, isn't that so? Are they worst?
Now about that X105BT Xpand type glasses mentioned on last page, are they better? Because they are really expensive.
Sounds like you have a 2013 model if the glasses that came with it are powered by a battery. I'm pretty sure all glasses that may came supplied with some 2012 model tv's and before were all rechargeable type glasses. The Samsung 5100's replaced the 4100's so you are correct in that. I see no difference in picture quality between the Samsung 5100's and Xpand 105BT glasses.