As WOW said, there is a big difference between high pressure /sleazy sales tactics and a company that offers reasonable incentives and provides thorough information about the service that they offer. You are making a very large investment, so you really want to get as much information as possible and get a good feel for the company that you may choose. Simply asking for the price alone is at the other extreme from the 3hr dog and pony show, you really want to be somewhere in between to be able to make a good choice.

@highport, are there any fiberglass manufs. you would recommend? @windowsonwashington, imo, the trimline is closer to the original casement because it is less ornate, (steel casements are very utilitarian looking and so the trimlines are closer in that sense) and also the frame seems narrower. I believe, at least an 1/2-inch per side-sash so a total of 1-inch per window more of glass? One of the things I am not so fond of on the OKNA is the ornate trim-molding-look their have to their frames. But I'm glad to hear its a solid product. One of the challenges is the original window detail. On the inside, there is not wood trim or molding but rather just a finished plaster surround on all sides. And obviously on the outside, there is just a caulk joint. They have assured us that they will use the tiniest trim mold for the inside and outside. Is it okay to ask a window installer for locations for where they have installed similar windows and for reference we can call? To date, they've only referred us to online reviewing website (insiderpages?) and had us look at a hardcopy booklet of customer survey/reviews. They were rather short coming when we wanted to see the exact product installed. We are considering the OKNA in the dark bronze color (have you had any issues with this color?) We've read that painted pvc might have some issues in heat and it does get pretty hot here in the summers. Our house faces east in the front and west in the back. We also wanted to see the window in the bronze color installed but again, the installer has not provided any info which I find a bit odd? We are considering the RSL (raised simulate lite?) - you know the divider details. I am not sold as it seems these are just glued onto the glass with double-stick tape. How do you think these hold up in duration of the product? OH, and we live directly across from a playground where the noise can be atrocious in the summer. I asked if there was a sound difference to a double-hung vs. a casement window and the installer said no difference. The biggest would be to get a hurricane type of insulated glass unit, where the outside is actually 2 layers of glass laminated together. Any comments on this?

Great point by Todd #2. The quality of the install and company behind it are huge and should not be discounted. On product, I'd generally agree with the recommendations above. If you can afford the 1800 that is a phenomenal window. There are not many choices on the market that can hit a .18 u factor with only argon gas. I'd look at the 500 as well if you are on a tighter budget. Perhaps there is some wiggle room on that one. After that, the Sunrise is pretty highly regarded. On Vytex, I have no personal experiences as I do with the other choices, however I have also heard a mixed bag regarding QC and warranty stuff.

@Joseph Corlett, you're correct on that one. My contractor tried to install my window with the packing tape type of flashing, and no sill flashing, and a half assed fiberglass insulation job. Pretty sure they're losing money because they got to re-do all of it, and replace some of my siding they broke in the process. They look great now that they're installed (properly). If the OP is buying windows purely on price, then I would expect the the installer's work to be in kind and he might actually be better off doing it himself. @luv2bhome2, the two double casement windows I just had installed were roughly 53" square, with the Ultra U Plus 8 (triple pane), white interior, oak interior w/ Madera trim and it was $5,340 installed. And that was the lowest priced bid around here (in MN). The other two bids were slightly more money and that was just with a double pane windows. I think they wanted another $200 per window to add triple pane. Given my issues with this installer, I'll likely pay the additional money to try the other contractors to see if they can install a window properly without me giving them a list of crap they didn't do right, or at all.