I just received two quotes for retrofit window installation and the difference in the amounts was huge. Vinyl windows from one company was much less than Fibrex windows from another company... it's a $4000 difference in price with Fibrex being more expensive.... why? Are vinyl windows bad to have installed.... this is what the salesperson who was peddaling the Fibrex was telling me.... can someone please tell me whether or not vinyl windows are really all that bad? I don't want to have to redo these windows twice so I'm trying to do my homework first before I make a decision. Thanks.