Getting Talia Shire and Burgess Meredith.
Rocky's budget was barely 1 million dollars.
Talia Shire by then had been in Godfather 1 and 2 (nominated for the Academy Award for Supporting Actress for part 2).
Burgess Meredith had also been nominated for an Academy Award and a Golden Globe for The Day Of The Locust the year prior to the release of Rocky, plus an extensive film and tv career spanning various decades by the time this role came about.
Seems like they would have commanded some sort of salary for such a small budget film. If the same movie had been produced today they probably would have given both roles to unknowns.
I wonder if it was difficult to convince them to take on these roles, or did they just fall in love with the script, or did they get some sort of backend deal... I mean they were both far from A listers, but still they were not 'unknowns'.
Much has been talked about how difficult it was for Stallone to make the movie and more than anything getting to the opportunity to star in it... but I have never heard about the rest of the casting process, only about Carl Weathers that he had the right attitude and was way too in shape for the role lol.