A lot of those places stay in business because they have very high pressure salesmen who do a pretty good job duping people into thinking those windows are a bargain. You'll get a whole sales pitch, followed by "and, we're having a trade-in rebate this week, you can get $100 for each of your old windows that you trade in for the new ones. So, that's $700 off. Of course, it costs the company a lot of money to send salespeople out multiple times to make one sale, so if you buy now, we'll reward you by giving you an additional 20% off.
yadda yadda yadda
I've gone through 2 of those sales pitches. They completely overwhelm the average person. Unfortunately, for the salesperson, I was able to recap all the places where he deliberately misled my wife (without actually lying.) i.e. "We only use virgin vinyl. Our competitor uses 10% recycled vinyl. Now, in order to get their recycled vinyl white in order to get consistent colors, our competitor has to bleach it. Mrs. Kenyon, what happens to the strength of the fabric in clothes after you've bleached them a lot?" "They get weaker." "Exactly. And, what do you suppose will happen to the vinyl frames if you bleach them?" "Ahhh, they'll be weaker." "Exactly. You're pretty smart Mrs. Kenyon."
Me: "Why does bleach come in plastic containers? You just intentionally misled my wife. There's the door."
Don't fall for the hype too much... Is it *really* worth an extra $1000 per window to save what amounts to $1 per year on your heating costs? As others have said, you can get custom fit windows from Home Depot, Lowes, or almost any other local building supplies store. They could probably recommend a good contractor in your area and you can get them for a fraction of the price.
