I have kept my boat at both Netsel and Marmaris Yacht Marina, and have moored in Marti Marina (and checked out prices for keeping my boat there, as it's only a half hour or so from Marmaris and is in a much nicer sailing area).
In 2013 for my 12.2 Meter yacht, Marmaris Yacht Marina was EUR 3200, Netsel was EUR 4800 and Marti Marina was EUR 6800. This was for 6 months in the
water and 6 months out, including liftout/splash and
cradle. Marmaris Yacht Marina offers a discount for Cruising Association members, and also credits you with an extra month, if you are away from the marina for a month within your 12 month period (ours always seems to span the renewal period and they NEVER credit us time away even if the other trips add up cumulatively to more than the month within the contract).
All 3
marinas allow contractors onsite to
work on your boat, but MYM charges a fee for them to access the marina, which is generally passed on to you!
Nothing in Turkey is free or
cheap. The quality of work can be first class though.
Cheers, PT
BTW. In 2014 I chose 10 in and 2 out MYM, and with the CA discount, dropped the fee to EUR 2800.