Brazil's berthing space at its naval port is pretty full as is. Brazil will need another naval port for a navy larger than Britian's. Yes, Brazil buys new submarines, acquires used frigates, and attempts to build corvettes and patrol boats. But the submarines claim a large percentage of their capital budgets, and rightly so. Its shipbuilding projects are delayed considerably by a lack of proper funding, it seems it takes a decade or more to build a small surface warship.
While Brazil has an old aircraft carrier, its airwing comes up lacking. Its air force is a F-5 Freedom Fighter air force, not useful on a carrier. In the future they might get some older French Etendards for the old carrier. Brazil is a large developing nation, still with lots of poverty among the masses. Their army thereby gets the first priority for funding, and rightly so, the air force and navy are second.
If the Brazilian Navy could acquire useful second hand submarines in great shape, they would. Since they can't, the bulk of the navy's purchasing power is used to buy new submarines. The government acquires a suitable small number of used frigates when they become available from larger navies.
I don't see this history changing anytime soon.