Just checked prices for Oktoberfest.

Flights are pricey, but not amazingly so.  However the cheapest hotel we could find was nearly £500 for just three days, and it wasn't even in Munich (instead in Eching 25 miles away).

When we take into account flights, accomodation, food and perhaps most importantly beer money it all adds up to at least a grand, probably more if the absolute cheapest hotels are unavailable or you want to actually be in Munich somewhere.  You could probably have two weeks in the Caribbean for the same price!

Basically it looks like Oktoberfest is impossible on at least my budget.