Ok... good stuff. Still trying to decide about being comfortable with the gift. In fact, the outcome of this research will help determine that.
The fact he is Turkish is one of my concerns. Although we are doing business in the US, I want to respect his values.
As an engaged young man who has started his own business, his financial situation is better than mine. (for now at least) Since he doesn't have the expense of a family to consider, it might be that the cost isn't an issue for him. He does come from a "wealthier" family, so his perception of money could be different.
It was also brought to my attention that he could also be considering this as a business expense and will write it off on his taxes.
We do work for different companies, but this is not an issue based on policies.
My googling revealed similar info regarding customs... as did asking friends and family. I was hoping for something more definitive, but it sounds like I'm going to go with a very nice Thank You note and then waiting for an appropriate opportunity to reciprocate.
I look forward to further suggestions, and thank you all for helping me get a clearer perspective on this.
Happy New Year!