The Superior Spider-Man [Campbell] #20 value

Based on the catalog data provided for these specific issues of *The Superior Spider-Man* by Campbell, the value varies significantly by issue number. Issue #1 is the most valuable at a used price of $627.90, while the later issues listed have much lower values, with #31 being the least valuable at $4.84 used. The value is clearly tied to the specific issue number within the series.