We do ErlangCamp at cost, more or less, as a service to the community. Generally it comes out to between a 100 and 150 dollars a seat. Considering the quality of the speakers and the material this is already really inexpensive. Spil Games generosity cuts that, already insane price, in half more or less. If you have an interest in Erlang and you are in Europe its nots not to attend.
Full Disclosure - I am one of the organizers.