what happens if you are on a level and take the upgrade for that level, will you have used your poin

Hi,
I'd like more info on the upgrades, levels and point system. So if I take the 250MB upgrade on level 1, will I not be using my points for that and restart the points to get to level 2? or the points stay regardless and I'd be able to get upgrades for both level 1 and level 2? Also are the upgrades cumulative(I.E. if I get 250MB and in level 2 lets say I get 500MB would that be 750MB total or one superseeds the other)?
Also, can you redeem both perk and an upgrade or only one or the other?
Thanks