I see weapons and equipment as explosives. Just as a different type....... They are Type B.
Type B . ...........Type B never get used up and they are permenent.... the more you get and more you upgrage them, the less % it adds too your defence and attack depending on upgrade. For example you have level 5 aug type B explosive and you upgrade too a level 9 M4 A1 explosive Type B...............you only get a % of the attack/defence actually stated on screen.... M4 Type B Explosive onscreen stats = 20A but it only adds +13 attack because its being upgraded from a level 5 Type B Aug 7A 6D.............
My advise is to just build the highest teir Type B explosives off the bat....... E.G As soon as you can start farming m4a1s for an instant level top teir type b m4 a1 20A 22D upgrade from junkyard do it...... no stat points deducted type b onscreen stats...............
As for Type A explosives who cares about them..... Only users with Type B inadequacy issues... thats who...........................