Heritage has a pair of Big Boy #1s for sale: Adventures of Big Boy #1 East Variant (Timely, 1956) CGC VF and Adventures of Big Boy #1.
As late as 1982, this was one of the top ten most valuable silver age books. The 3x return on your $350 investment in the early 80s is pretty crummy when you compare possible a 500-1000x return from a NM Fantastic Four #1 ($1100 at the time) or Amazing Fantasy #15 ($1000 at the time.)