I haven't tried it yet, but according to Amazon's site, the only reason the recipient would not receive the gifted book is because of copyright restrictions for their country, in which case they are given the option to exchange it or receive credit in the amount the giver paid for the gift. They also specify that "there is no charge to receive a gift", which implies that they do not charge the recipient in the event of a pricing difference.
More info here:
Kindle Gifting