I have been doing this for a while. Sending money from Europe to Sosua and back, transferring ? in a small scale, for people I know. I cannot compete with WU, but 3 days is usually a good time to send/receive money in ? for only 2.5% of the amount.
All you need is a little cash on both sides....
It?s still not enough to live from this, but maybe one day, if satisfied clients spread the word.