You can see that it has the O2 extender on it, so that adds the extra $30. You can get it shipped direct from UR for $630.00 USD, so this would be an $130 discount (local) or $80 discount shipped. Not bad for a brand new DP that is sought after.
OP, tax will not apply unless someone buys it from a vendor in a state that does business in their state (although you are supposed to pay the tax later on your tax return in many cases...not sure if it comes direct from Canada).