$1500 to swap muffler in tips? If so I'd have to disagree, I've gone this route on my last two trucks and my costs were:
muffler -$45-50 (obviously this can vary depending on what you get but I love the cherry bomb exteme and have gone with this my last 2 exhausts)
tips- $51/each so around $100 total, and yes for 5" tips. I got them from summit racing and the inlet diameter was slightly bigger but since I'm already taking it to an exhaust shop, I don't worry about that because they can easily make it work. Also should mention the last two times I bought these they were only available in chrome so I did have to paint them myself.
Labor for muffler and tips swap- $150-200, the $150 was a friends deal so to be fair lets go with $200
So my total came out to around $350 installed, plus my time to paint it and the cost of a can of high heat paint.