Perhaps we can do a few relative calculations to the pricing of Vista here to figure what we will be up for ...
Not looking to do USD conversions, just looking a pricing in local terms based on the relative cost of Vista vs Win 7 in each market.
Looking at Full Retail Editions, and using cheapest available current Vista pricing in NZ as a guide (as shown on PriceSpy):
Home Premium Win 7 16.7% discount in US on current Vista HP pricing.
Current NZD price of Vista HP is $401, applying the discount above yields a guess-timate of NZD $334 for Win 7 HP.
Professional Win 7 pricing is a little more difficult given Professional is a super-set of HP, whereas in Vista Business was not a super-set of HP (lacked WMC etc). Similarly for Ultimate versions.