Are there any cheap domestic flights to ESB? Perhaps some low-fare airlines Im not thinking of...or are domestic flights within Turkey pretty pricey? TK looks like it charges about $300+ for domestic roundtrips from IST (at least during June of this year according to ITA).
Pegasus Airlines offers service IST to ESB but (apparently) not the other way. I found a US$80 one way fare with them.
Wikipedia maintains a list of
all carriers that serve ESB, and it includes several European discount carriers from a few different gateways.
There is
train service between Istanbul and Ankara. Scheduled time each way is 6 hours or less.
There's also a lot of bus service.