Hello again Marchmont.
Having had a quick look it seems as there are only 2 flight options for Edinburgh/Dalaman.
The major tour operators and flight only agencies all seem to use Pegasus Airways, hence all have similar prices of around £280 - £300 each.
The second option is Onur Air, whose flights are available in the UK through
www.holidays-4u.co.uk or
0870 444 3843.
Depends on when you are looking to travel, but having put in a number of speculative dates, I am getting prices of around £179 each.
Hope that this helps.