Apart from the time and expense (www.lowcostconservatory.co.uk/upvc-conservatories-cost)that goes into building your conservatory there is the task of adding blinds and furniture. With the popularity of conservatories these days, there is a large choice of furniture retailers and an even bigger choice of furniture.
Timber conservatories are that much more expensive than PVCu and aluminium. In the end it is probably the budget that is the ultimate deciding factor when it comes to the choice of conservatory. See more here: www.orangerycosts.co.uk/modern-contemporary-orangery-home-extensions