I dunno if this fits your era but there are a whole slew of oddball sets from the 1960s-1970s that are challenging and fun. Some can run a few bucks but nothing compared to earlier cards. Some examples
1960 and 1961 Nu Card. People are starting to realize that this set has career-contemporary cards of Aaron, Mays, Musial, Williams (1960), McCovey RC, and some others I don't recall. Slabbed can cost you but nice raw cards are still a deal.
1968 Atlantic Oil. Forty cards mostly HOFers. The game ticket packaging makes condition an issue but if you don't insist on high grade there are plenty of career-contemporary HOFers for reasonable prices.
1961-63 Post and Jello cards are very reasonable.
