It’s not unreasonable to try and get the best deals for fully fitted replacement uPVC Windows, why wouldn’t you? But if you are going for rock bottom prices then you may have to compromise on a few things in order to achieve your goal. but visit this site to learn more: www.upvcwindowsfitted.co.uk
You could avoid using low-e glass, reduce the amount of opening sections, slimmer frames and also fit double glazed sealed units with smaller gaps without gas filled centres.
Casement windows are probably the simplest design and in terms of cheap double glazed windows this may be the design to investigate first. A word of caution, make sure that if you buy cheap double glazing it means that the cost was low and not that the windows is of ‘cheap’ quality materials and badly installed.
All your savings will literally go out the window if you end up with bad workmanship and rubbish products.