We recently redid ours - I'd hate to say a price as they may not compare around the country.
What I will say is to remember that there are 'premium' installers and regular joe installers and quite a spread in the prices quoted. Shop around and get lots of bids.
THEN, carefully understand just exactly what you are buying. In our instance the quote man assured me the guys would replace the old wood surrounds on a few of the windows and added $$'s to the ticket to include that work but when the installers got here they wouldn't perform.
We also paid 1/2 down and 1/2 after completion. I wouldn't pay my second half until they reduced the ticket for the work they didn't perform. So, protect yourself. My installers did just that INSTALL windows. Initially, they didn't do ANY repair work to the surrounding woodwork that needed doing. So, unless you get someone who will guarantee that they'll do any repairs needed as they go, then don't let them remove your windows unless you yourself are a carpenter w/supplies on hand OR you can have a carpenter on standby. You don't want a gapping hole in the side of your house while you try to locate an available carpenter.
This was a real issue w/us as one of our windows needing additional wood work was on the second story w/sloping ground underneath. We didn't want to be weekend warriors on this particular project and risk our life and limb that's why we had it quoted into the price of the window install. So, be careful. SOME installers may be perfectly happy sticking a new window in a rotting sill. If you don't want that to happen, be aware and have alternative plans. I wish our sales/quote guy would've been more honest with us about what his guys would and wouldn't do, some of what he said may have just been to get the sale, KWIM?
We worked around this issue and got our iffy situation straight - it did involve a call to the business owner and a promise to call the Better Business Bureau. Our new window got uninstalled and woodwork done then new window reinstalled. Shouldn't of had to make that call!
They reluctantly did the one second story window and we did repairs to the other ground level ones ourselves after they left. But we did get a reduction for the work they didn't do - had to remind them to take it off the ticket - like it was such a surprise that we didn't want to be charged for work not performed! Amazing!!
The other thing they did that I didn't care for was to take off the old awnings and drove off and left them in my yard for a week or so. By contract they were to dispose of them. They did finally perform that too, but in the interim they were trashing up my yard. I'd want a guarantee that any debris be removed the very day it was removed from the house.
We also got a new sliding door at the same time. I'm very happy with the windows & door we got, the installation thereof was a bit more of a situation where the craftmanship left a bit to be desired. YMMV!