Week 3 of DC's Convergence sale includes more 70s/80s/90s goodness and ends 4/27/15. I believe this is the first time that any Alan Moore Swamp Thing has been on sale.
Batman and the Outsiders 1-21
Green Lantern 180-200
Sage of the Swamp Thing 1-28
Omac 1
The Flash 340-350
https://www.comixology.com/Convergen...Sale/page/6258
Another Teenage Mutant Ninja Turtle collection sale: 20 books (10 from the newish IDW ongoing series and 10 from older runs) ending 4/27/15.
https://www.comixology.com/Discover-...Sale/page/6277