As part of their big post-Convergence relaunch, DC is offering a massive digital sale this month. The first wave, from today through June 8, features issues #1-38 of the New 52 Flash series at 99 cents each. Upcoming weeks are listed at DC’s blog
This includes almost all of the New 52 Flash series: The entire Manapul/Buccellato run, plus the first year of the Venditti/Jensen/Booth/Rapmund run, with a few exceptions: The September one-shots (#0, Villains Month, Futures End) and Annuals aren’t included, but you can still get them at their normal price.