There are almost 70,000 shares being sold for less than .009 on BF.
It'll mostly stay this way for the next hour, and an hour is the time needed for any BTCTC investor to sell, transfer to weex, wait 6 conf, transfer to BF and buy for a nice profit.
You have to wait 3-24 hours to get money out of btct. There is also SDice cash that has yet to actually appear I think so arbitrage is very risky right now, even with the two 30k walls.