I was watching a few of his cards and had the high bid on one of them, then he withdrew them. I sent him a message asking if they were still available. He responded by saying that he was sorry he withdrew them and wished me good luck.

I can't say that he wasn't polite, but I don't know what happened to the cards he was selling.
He pulled quite a few auctions.

Is this normal behavior for him?

No clue as to his last name.
It's bad enough that eBay has been dead, now when I find something I really want, the seller withdraws them.