One-currency Saarc?
The idea must have some validity, otherwise it would not have been floated by a big international agency. It greatly suits the export and trading interests of the industrialised countries, with less hassles, formalities and paper work, and faster movement of raw materials and finished products.
The regional partners or players have two main problems, to start with making the system take off quickly (lot of pin-pricks) for internal movement (sys-loss); and overcoming import restrictions in the countries of the foreign buyers, both developed and developing.
This time-lag is worth hundreds of billions of dollars; one losing, and the other gaining. The UN agencies cannot cope with the cunning devices of the superpowers (of. Iraq). WTO is a glorious failure (as anticipated).