this is math, man... it's not my logic, you can't say 4% based on a subtraction of the inflation rate from 8 to 4, that's not correct

if you want real numbers then you should compare the total coins that will be less dumped(presumably 1800) with the total coins(including the mined coins) that will be dumped each day, or that are dumped each day

if for example the total coins dumped per day is 10k coins(i doubt is so high) per day for now(including the 3600 mined coins), with the halving this will lead to a reduction of almost 20%(10k-1800), which mean that the demand will go up by roughly 25%

this assuming that the demand will remain the same until halving, so even if the demand will remain the same and the price the same, with the halving alone the price will increase by 25% which mean around $360