No joke there.  Until some 20 years ago, technical conferences used to be organized by reputable scientific societies, and the organizers "played to lose": they looked for the cheapest possible venues and formats, and begged money from sponsors, so that the registration fee could be as low as possible.  Often the conference ended in the red, and sponsors had to be begged again to make ends meet.

But in those 20 years things have changed.  First there were many entrepreneurs ("Nagib Callaos" is a legendary name there) who saw technical conferences as an opportunity to make money.  They would organize humongous conferences, with dozens of parallel sessions, high fees, in popular vacation places; and accept absolutely any garbage that was printed in eight US letter pages and had a title and authors at the top.  They made a profit serving the huge market of mediocre university profs who needed publications in their resumés but cold not get their papers accepted into the serious conferences.

For a few years, serious conferences would still try to keep registration fees down; but then the sponsoring societies realized that they too could use the conferences as a source of revenue, instead of a service that was part of their mission.  IEEE was one of the first to do that (some IEEE top guy even resigned in protest), but others followed.  So, the fees that used to be 150-300 USD are now 1000-2000 USD...