British Airways, Finnair, and Iberia have round-trip flights from Austin (AUS) to Mykonos, Greece (JMK) for $685-$717 with a connection. Flights August to September. Departures on Monday, Tuesday, and Sunday. 7-day minimum stay required.
This requires an overnight in London, but I know some of you know how to make good use of that. The Tuesdays and Wednesday returns have the longest layovers.