Hi Kazza, good luck with your new business!
Rules on taking money out of Turkey can be found at point 11.7 on this page of the Turkish Economy website:
http://www.turkishec...ty/residing.htmI also don't think there is a limit to how much money you bring in.
However that page also says that there is a limit of $5,000 for cash transactions, more than that and you should be paying by bank transfer. So unless you are buying a very cheap business, transfer the money by bank transfer instead of bringing it over in cash!
As a general point though, I would suggest that unless you are a money launderer, you should ALWAYS move large amounts by bank transfer. That way there is a paper trail if something should go wrong. And of course, all legal documents relating to your purchase should be notarised here in Turkey, in the presence of you and the seller of the business. I have seen so many people fall victim to con artists (and not just in Turkey) because they've taken a short cut / tried to save £100 here and there. It's not worth it.