I can't imagine, if he is truly doing arbitrage, that he isn't making an absolute killing right now. But in terms of USD, he owes about half of what he did just a few months ago.
I haven't seen it like this in a while
The spread between bitfinex and stamps has averaged 10 dollars since stamps went down
But yea, fuck, just buy 30 coins and you have half as many people bitching at you to get repaid
If he actually is doing arbitrage then he can repay himself.