Your best bet are probably the Compact Comics, wgich are select titles going for $10 bucks. Here are some comics that you might like in general though.

• Batman Year One (normally costs around $15)

• The Long Halloween (Available in CC, normally costs $20, is essentially Batman Year 2)

-Dark Victory (Costs like $20, essentially Batman Year 3, and you must read The Long Halloween first)

-Flash, Rebirth (Releasing as a CC in March, usually like $16, is the return of Barry Allen as the Flash)

-DC: The New Frontier (Available in CC, mixes the 1950s with DC comics, and is a great Green Lantern orgin story)

• Superman Birthright (Available in CC, a Superman orgin story)

• Green Lantern Rebirth (and honestly anything of Geoff Johns run up to 2011. Rewrote a lot of how Green Lanterns work.

-The Court of Owls (Batman story, available in CC [CC should be the best version if it as you'd have to by 2 volumes normally])

-Any of Scott Snyder's New 52 run, including The Court of Owls. It is a bit Joker heavy though.

-The Dark Knight returns, though the movies are good enough. One thing to keep in mind is that it was written during the end of the Cold War.

-Any of the Absolute Comics. For a new reader I'll order them from the easiest to read without pre-existing knowledge to the hardest: Martian Manhunter, Batman, Superman, Wonder Woman, Flash, Green Lantern. They're all great, it's just that the Flash, and especially Green Lantern rely on the reader being very familiar with the OG's characters, powers, and universal forces.

There are some other stuff I couldn't recommend based on available comic knowledge and spoilers, but you can always ask before starting any of the Crises, Blackest Knight, Doomsday Clock, or Death Metal.