I find as I am getting into my 5th decade of collecting that my interests are more esoteric and obscure, and low cost. I was always more interested in offbeat and oddball card issues than mainstream, but now it has slipped into non-traditional sports, non-sports, premiums, team issues, and photos. Thankfully, not publications. The projects I enjoy the most right now are:
--Vintage NASCAR postcards
--Prewar Art Nouveau and Art Deco prints and postcards from Japan
--Comedians and musicians cards and photos
--Sports photos, especially vintage snapshots.
--Matchbooks and matchbox labels
--Nonsports
Almost none of it is valuable or expensive as compared to sports cards.