I'm currently sitting at a 10% discount from Intel upgrades (2x 5% discount), but I'd like to know what the maximum potential discount is. Considering weapons and mods carry over into New Game+, what I'd like to do is just buy up as much as I can afford as I near the end of the game so my squaddies will be better kitted out for Insanity (I don't use weapons much myself on my Vanguard).
Is 10% the maximum? I've got Priority: Horizon in my Journal as my next mission, and the galaxy is currently 100% scanned.