No one knows how long Disney will keep bridging, but it is a money saver when you buy from a Disney authorized ticket seller. I buy from
Undercover Tourist. I bought a 5 day park hopper for $367.00 before prices went up, so that price is no longer available. WDW cost for same ticket is $435.59, so I saved $68.59. If I want to upgrade to a 7 day park hopper, I pay $31.95 extra, for a total of $398.95. WDW charges $467.54 for the 7 day park hopper, so I still save $68.59. If I want to upgrade to an AP, WDW (currently, no one knows how soon WDW will stop bridging) gives me $435.59 credit toward the cost of a new AP. So I still save $68.59.
http://www.disboards.com/threads/everything-about-wdw-tickets.1452684/
This is an old thread, but the advice is good and true. Cheshire Figment used to work in ticketing or guest relations, and explained all of this to us. He has gone to be with God, and is sorely missed.