cost of replacing window sill

about how much does it cost to replace a window sill? (average) also window capping? i am having 12 windows replaced.

$100-$900 each.

How long is the sill?

How bad is the rot?

Does the rot extend into the stud cavity?

How many bends in the capping?

What color?

Are you a nice person?

I could go on for pages with questions, your best best is to have a skilled installer/window rep take a look at your sills and capping needs. Generally within a minute (without rot issues) they will have a price in their head.

on average,75- 100 bucks.

Krypton, 75-100 for sill nose or the whole sill? Does that include capping?

$150-$300 for whole sill - redwood sill unfinished.

capping $50 extra

We usually replace a sill nose at no charge. Full sill, depends on situation, probably $100-$200. Capping $65 per standard size opening unless it is some kind of crazy exotic bend or uses up a ton of coil.