Pre-paid cards will probably face a legal issues in most of the developing countries, or at least legalization will add too much cost to be useful.
Two days ago i had some money at last to buy some NuShares, the only way to access the online markets was to buy Bitcoins locally from LocalBitcoins.com for +10% price spread, gave the trader the Bitcoin address from ShapeShift.io and got my NuBits immediately to be safe from any surprising volatility, then I had my time to buy NuShares with the best price I can get from the exchanges.
The conclusion is, if NuBits got so popular to have a LocalNuBits.com , it will be the best option right now to access the cryptocurrencies markets and transfer money globally. however, there will always be a price spread for the local traders to profit, unless local traders are a custodians who get their profits from Nu to keep NuBits at $1 and keep Buy liquidity locally (offline) everywhere.