Hi I'm going to Oludeniz next June and want to do a few excursions,is it cheaper to book in advance online or when you get there?
I would always suggest you wait until you get there, there's not much difference in price and you may change your mind on the day you chose or the weather isn't suitable etc. There are plenty of options and agencies are usually competitive, make sure you choose a reputable local one such as http://www.tinyakropol.com/
I agree with Scousemouse, Book when you arrive, lots of places to book and they all give good prices. Booking too far in advance means days you have booked to go you may not feel like moving, also in the unlikely event of weather being bad, you have no choice but to go.
I also agree about Tiny, good company. We did a trip to the Greek Island of Meis with him last week and it was excellent service and a very good price.
I book before I go. Carole and Tayfun give really good prices and service. They are on Facebook and they have buy two get two free just pay for the transfer from your hotel for the free ones
We have used Guide Tours over recent years , go and see Tara in the booking office near the top of the Dolmus Road next to Inci restaurant. Have a look at the web sites of the companies mentioned to get some idea of what you would like to do and an idea of prices, all much the same though . Would not book in advance for reasons previously stated and that prices may change depending on the exchange rate .
If you do book through Guide Tours , ask if Mehmet is going to be the guide as he is excellent , very knowledgeable on Turkish history and speaks good English.