To see more about different types of conservstories & how much they cost, go visit. www.lowcostconservatory.co.uk/replacement-conservatory-roof-cost
Conservatories as a Home Extension – how much do they cost?
But as a general guide, you are likely to pay anywhere between £10,000 and £30,000 and there is more price dtail here: https://www.conservatorypro.co.uk/lean-to-conservatory-cost/
This is a wide margin, so it is always advisable to shop around before you make your final decision