According to who? If we assume normal supply/demand rules apply (because why wouldn't they?), the countries which ban bitcoin will have to buy bitcoin for a lar

According to who? If we assume normal supply/demand rules apply (because why wouldn't they?), the countries which ban bitcoin will have to buy bitcoin for a larger sum, to take into account that the trading is now illegal. Because the demand won't disappear just because you make it illegal, we've already seen how this works in practice with illicit drugs.