What is the ruling on buying electronic dollars in Tunisia at a price higher than their real value due to the difficulty of transferring money abroad?

It is permissible to purchase electronic dollars for more than their value in Tunisian Dinars, due to the difference between the two currencies, but on condition of immediate possession—even if constructive—such as a bank entry for a sum of money in the client’s account, while observing the Islamic rules of currency exchange. A delay in the bank entry is excusable to the customary extent, but the beneficiary is not allowed to dispose of the currency until they are able to actually receive it.