The Collectibles Shop has back issue Silver, Bronze and Copper/Modern Age Marvel comics for sale, well below guide prices, from Avengers to Spider-Man to X-Men and many in between. Some graphic novels too, well under cover price. All are Near Mint, first prints, complete, unless noted.
Pictured is the Avengers King-Size Special #3 from 1969, VF+ 8.5, for $35. Reprints Avengers #4, the first Silver Age Captain America appearance.