My regular customers include a window salesman, and a window surveyor (goes round after the salesman has done his bit and actually measure the windows etc). Unfortunately, the latter is on holiday this week, but I'll check with the former this evening if I remember. He's an ex-salesman as of last year, so should be honest about it. From conversations with him, I can advise you to beware of all the "pay for the front, get the back free" deals etc, as those sort of companies will be ripping you off anyway. The salesmen are amongst the most highly-trained, aggressive-style of any trade. You do not get a bargain from them, even though you will think you do. Some of the techniques he explained to me were quite scarily akin to military interrogation. I'll let you know what he says either tonight, or tomorrow morning. There is another way, though. If they are standard sizes, the window units themselves do not cost much (think 10% od what you get charged) and a pair of competent builders/handymen should be able to fit them.
[rab] Everest claim to be the best, but are probably the most expensive. They did six floor-to-ceiling windows and a door for me years back for 4k. How long do you plan staying at the address? You don't want something that will need replacing again in less than 20 years.
I've spoken to my mate, who used to work for StayBrite. He says there's a huge window-making company in Edinburgh that the likes of Staybrite buy their windows from. He'll try and track down the name tonight. He also reckons that, if there are no complex openings required etc, that you "could" get it done for £2K-ish. His advice is find a reputable window-fitter, not a big national company - you get the same windows, a non sales-driven company, and half the price. More to follow when I get more info.
Anyone seen Inkspot lately? He and I (as sigmundfreud) seem to be the only two left on Celebdaq. I'm really hanging on so he doesn't feel in solitary splendour. I suspect he's doing the same... Alternatively, some of you deserters might re-join.