Here's some recent experience on a DONE4 quoted for my wife ex-MRU, followed by a ticketed one ex-ARN last month. (Note currency exchanges may have changed.)
When we did the comparo and added the marginal cost to get to MRU plus accommodations on the island (why not see the place if we're going there) we concluded that ARN was a better deal. BTW, getting to MRU on award miles in J proved quite impossible for our days - even IB to JNB was plugged.
Both itineraries 16 segments (for e-ticketing) and no UK stopovers.
Code:
Price quote, DONE4 MRU (BA) May 2007
(MUR converted to USD)
Base price $5157
Taxes/fuel 668
Taxes as pct of base 12.96%
BA service chg 300
Total cost $6125
Taxes/fees as pct of base 18.78%
Ticketed DONE4 ARN (AA) June 2007
(SEK converted to USD)
Base price $6405
Taxes/fees/fuel 331
Total cost $6736
Taxes/fees as pct of base 5.16%