You can't bargain over a fish still in the sea.
What do you think it means?
Denizdeki balığın pazarlığı olmaz.
Meaning
Don't haggle over something you don't have yet.
English equivalent
Don't count your chickens before they hatch.
In Turkish: Denizdeki balığın pazarlığı olmaz.
Meaning from the TDK (Turkish Language Association) dictionary.