Lol, of course it will. These devices will keep inching on the pricing with every release until we stop buying them.
Don't get me wrong, the iPhone is a superb smartphone. If I were Apple's CEO, I'd probably have and unspoken target to push the prices up as long as unit sales weren't impacted too much. As soon as sales taper off, I'd lower the price overnight and hand it to marketing to spin the story for the masses.
Did you see the lineups of people buying them? Even locally here they had to have security people and queues to keep things organized. And people in some countries were lined up in the hundreds to buy and resell at even higher prices than what they paid.
There are lots of people with enough disposable income to buy them even at current prices.
Still have my 13 Mini and see no reason to "upgrade". The difference between model generations is less than paper thin these days, especially if you're not into using your phone as a camera.
My advice would be to wait for the 16 to buy a new 15, you still get a brand new flagship phone at a significant savings. Also it's not like there are many feature differences between each model these days.