I love these posts, partially because I end up buying a bunch of slabs as I am researching it. There are a ton of cheap graded comics on eBay. Here are some of the highlights.
These are all 9.8 CGC books (none of them are owned by or for sale by me).
Teen Titans #15 (New 52 Joker Mask Variant) – CGC 9.8 The sweet Joker Mask variant that took off when Joker had his face cut off.
Avengers #36 Hasbro Variant – CGC 9.8 (this seller has a ton of slabs at under $20.
Ms. Marvel #11 – CGC 9.8 Kamala Khan slab for under $20.
Ms. Marvel #12 – Same as above. Hot character at under $20.
Wolverines #1 – Leading up to the Return of Wolverine for under $18.
Black Science #3 – Recently optioned Rick Remender series
Black Science #4 – See above, recently optioned Rick Remender series.
Spawn #264 – Spawn cheap.
Amazing Spider-Man #794 Comicxposure 3rd Print – CGC 9.8 Norman Osborn gets Carnage.
Amazing Spider-Man #797 – Red Goblin Storyline.
Amazing Spider-Man #797 2nd Print – Red Goblin (free shipping)
Amazing Spider-Man #798 Humberto Ramos Variant – More Red Goblin goodness.
Thanos Legacy #1 George Perez Variant – Classic Thanos art. Free shipping
Thanos Legacy #1 Cosmic Ghost Rider Variant – Cosmic Ghost Rider. Free Shipping.
Thanos Legacy #1 Ron Lim Variant – Rounding out the Thanos Legacy covers.
Star Wars #1 Hastings Variant – Star Wars’ return to Marvel.
Catwoman #2 Artgerm Variant – Recently released Artgerm cover.
You can see the full list here.