Caleb,
I have an Aeronca L-16A, ( military version of a Champ) and it, and the Piper or Taylorcraft versions are
the closest thing to "trainer" "Warbird" you will find at costs far below even T-6 or T-28 levels.
I flew to Oshkosh last year, and wondered if I would be welcomed by the hairy chested, big buck WARBIRD
guys, but as I was told, "It's a Warbird, welcome to the party".
Cost varies widely, but due diligence and research will find something for you.
good luck in your search.