how it functions: when upgrading from t1 to t4, it will price the item as 5600 instead of 4800 and then additional 800 from t2 upgrade, which was how it used to work, now it is just purchasing the t4 for 5600 and providing the t2 for free, but then when sold, it will sell the t4 for the price it was purchased at (5600) as well as refunding the price for the t2 that you didnt purchase (800), which ends up giving you 6400 in return, same works with cooldown but instead of 800 from getting a t2 for free, you instead get 1600 for getting a t3 for free