If there is a chance that you can open Turkish bank account, do it. Ask banks. You probably at least need short term residence permit for Turkish bank account but I'm not sure maybe there is an other way. Than you can sign up to one of local exchanges like Btcturk or Paribu (they're pretty safe and you need KYC). You can exchange your crypto to TL at these exchanges, withdraw to your bank account than transfer it for the property. It will save you both money, time and you won't need to trust third parties. Turkish person can do it for you but yes you need someone to trust in that case.
If there is no way for you to get bank account, I still have some advice: I don't recommend fiat $ to TL conversion through bank, they have very bad exchange rates most of the time (sometimes %3-4 less than you can get from Btcturk or Paribu) Some banks has okay rates but most famous banks will rip you off. It is also possible to talk with banks beforehand, they probably can offer you better rates for big amounts of money. Don't accept their rates upfront, research. If you still need to do that irl, there are irl money exchanges with good rates e.g. in Fatih, Istanbul. Try to avoid touristic places. But this will also bring some security problems, as you need to carry big amounts of cash. Need to have kind of security for this I think.
Thank you for your answer! Problem is that according to turkish law you have to (as a foreigner) to change the money to TL to get "Döriz Alim Belgesi" otherwise you won't be able to get the Tapu.
And also it has to be crypto -> cash (without banks), there are a couple of exchange places in e.g. Istanbul according to
https://www.bestchange.com/. Are this type of places really trustworthy?
But yeah it's always a risk to travel with alot of cash I guess, not sure how to organize some type of security without getting ripped of by them.