What is meant by Price Extensions?
Extension pricing is a strategy where a company has standard prices for its products across all locations and geographies irrespective of any other factors. In such a case, shipping, taxes and other expenses are covered in the standard price. It is one of the pricing strategies used by companies.
Price Extensions are extra snippets of information about your specific products or services that can be added to your AdWords text ads. They initially beta-tested in English and $USD, but are now publicly available to all advertisers in 24 languages and currencies.