You need to charge over 4000 RMB (about $600) to get EBB7 (Connecticut) and 2000 to get Oklahoma - this is a rule of KPcoin accumulate event. The good thing, that you can charge kpcoins only when you have x2 coupons from Kupaisky and then you will need to spend about $300 (but you need to wait for coupons).
Charged kpcoins can be used in Supplybox event. 1 gold key to open the box costs 10 kpcoins, but you need to buy 10 keys at least. So if you want to have a chance winning the ebb7, you must spend 100 kpcoins.
Then you open the boxes (10) and if you are lucky, you can get the ebb7, but there is a risk you will not get desired ebb7 (prizes are randomly selected).
So if you’re really looking for specified ebb7, you must spend 300 bucks at least.