Friends are in Zakynthos at present. They booked through Cassidy Travel, Dundrum Town Centre, and had the option of self catering or 3 star hotel B&B. They chose the latter and are having a brilliant time - total cost for two people was under €1,200 for 2 weeks. They booked about 10 days in advance and the holiday had been reduced from around €850 pp on the Panorama brochure price.
There are 7 day s.c. holidays to Mykonos listed on the [broken link removed] website coming in from around €429 pp for Wednesday 13 August.
Hope this is of some assistance.