My daughter and I went to a comic book show, and I found lots of very reasonble priced Silver Age D.C. comics to fill collection holes. I got:
Justice League #45, 75, 97, 99, 107, 109, 122, 137 & 141 (1966-1977);
Teen Titans #12, 37, 40, 41 & 43 (1967-1973);
Wonder Woman #138, 203 & 219) (1963 - 1973);
World's Finest #220 (1973).
I also found for either 50-cents or $1 several current issues of Extreme X-Men, Avengers, Electra, Daredevil, Ultimate Marvel Team-up, Wolverine, as well as some Buffy and Angel issues for my wife, filled two holes in my Thunderbolts collection, found an old Captain America (#182 from 1974), and at Piratecat's recommendation picked up Volume #4 of The Adventures of Barry Ween, Boy Genius.