There are a number of basic issues in the Brazilian league which are stopping the league from exploding
The biggest problem is the power given to small clubs and the states/counties. This results in Brazilian clubs spending half of their year playing in local leagues. It would be the equivalent of Arsenal spending half the year in the Premier League, and the other half of the year in a competition with Barnet, Dagenham & Redbridge and worse. Lots of money is lost in this process versus if they had a full year of National Championship. There are over 20 such championships, and they are not going away anytime soon because power in the football association is state-based versus being club based. Therefore, each state, especially those with big clubs, is incentivized to hold its own contest.
Basically, until the clubs need to get rid of the state championships, increase the TV money flowing into the game (which would also be a function of, say, a breakaway Premier League), and improve branding. With these advancements, the clubs then might be able to afford big players. For the time being, the only way to afford a good player is to allow someone else to pick up part of the transfer fee and wages.
Basically, the best thing that Corinthians, Santos and the others can do is break away and form a Brazilian premier league that is unhindered by the state championship layer.