I can see this going till next year to be honest
There has been no rumours at all regarding this
If you can, buy it now and he can maybe sell it when the new one arrives
I have came to the conclusion now that I just can't keep up with Apple, im fed up now of the small updates on the iPhone's that I've literally now stopped updating every year. I'm losing too much money and it's only feeding Apples pockets, I should be happy what I have now and use it to the full