Unlike other events in high demand, Bayreuth does not raise its ticket prices to astronomical levels (you pay $200 for top seats, quite reasonable compared to the Met or ROH). So there is big demand and no market mechanism to counteract it.
In order to get tickets, you need to apply,in German, french or English to the box office at the festspielhaus in october. You get rejected and try again. Each time you are rejected you move up a little in the queue - until you get tickets after 8-10 years.
Becoming a member of your local Wagner society helps - you may get higher priority or the society may get an allocation.
You can also join 'Friends of Bayreuth' - www.freuende-bayreuth.org - for a joining fee of 260 euros and 205 euros per year. This gives you increased priority (maybe you wait 2-3 years instead of 8-10).
Donating to Bayreuth gets you quick tickets - apparently $5000 a year pretty much guarantees you tickets every year.
Basically you need either lots of money, or lots of patience.
Im not sure which virtue Wagner would have preferred his 'pilgrims' to have!
I wish you'd been logged on so I could give you a trust point recommendation. Please keep contributing!