re: Do actors doing cameos get paid?

A spoken line on film can be worth a lot.... The number of lines, the length of the show, the type of show, a recurring role etc makes a difference. SAG-AFTRA rates vary on everything but for a full length film (over 90 minute long features), pay is $650 for five lines or less for actors with one shoot day. If they shoot for multiple days, it goes up dramatically

If a studio wants someone badly they can pay the actors asking rate. So for a cameo, they are required to pay the SAG minimum unless the actor requests more. So it completely depends upon how production/the actor wants to play it... I doubt that the anchorman cameos cost much because I dont think that all of those A-Listers charged their quota. It's good publicity for them to be in the movie and they can always hit up Ferrell later to return the favor and do a cheap cameo... But regardless: yes, they do get paid.