Hi Mat,
flights got a bit more expensive recently. In that case I would check the different agencies from time to time. If you check "
http://www.expedia.de/pub/agent.dll" you find a return flight from London Gatwick to Mauritius for 756 GBP with Emirates.
If you are flexible due to the dates you could wait some more time trying to get something cheeper if you are lucky. We sometimes booked just ten to twelve days before leaving Germany and got like special offers with Air Mauritius.
Good luck and all the best,
Brofasond