IMO, 10 BTC is a hugely inflated price for an empty bar. However, that is approximately what a 1,000 BTC empty bar sold on ebay.... so I guess that's the going rate. Yes, this guy is trying to say that an empty, gold plated bar is worth 100 times that.
It's common for collectors to over-value their goods.
i imagine it only sold for that value as it was a tax write off / donation....unless i am mixing two auctions up

No, it was the same auction. I agree, i think that it would have been a lot less if it wasn't going to charity and coming directly from Mike himself