One of these sold for $10,000 on eBay last month. I bought these in 2011 directly from the Casascius website. Turns out these are the extremely rare one's with the misspelling in the word Casascius, making them extra valuable.
I bought this one with the same batch, I don't even know how much it is currently going for. If you know, let me know in the comments. Also 2011 with error:
I have not sold any. I'm HODLING for the long haul. But I've been adding a few more to my collection here and there:
Recently added a silver 2013 0.1 BTC coin and a 2013 0.5 BTC coin.
What does your collection look like??