finding travel ticket

I need to be in Istanbul, Turkey, on 15 Oct 2016, traveling from Dresden Germany. I'm open to leaving Dresden on the 14 th at night as well. I need to be back in Dresden from Istanbul on the 19 th morning; 18 Oct at night is acceptable too. The whole flight duration between dresden and istanbul shouldn't be more that 12 hours. Use your imagination, like: maybe take a bus to berlin, then flight to romania because from romania to istanbul is cheap or so. It's up to you. But, the final whole journey price including the return ticket should not be more than 150 Euros.