The money thing? Well, it all started since "Money" on DSOTM, then the whole "Animals" album with the Dogs and Pigs analogies.
The arena thing? Since 1977 and the infamous "spitting" incident during the "Animals" Tour. He wrote "The Wall" as a reaction against touring and arena shows. He said the wall symbolized his detachment from the audience when he played a concert.
It's funny. He repeats the same things on the "Wall" DVD, yet his last tour was as huge and impersonal as they came. Aw, well.