Your biggest headache (apart from saving the money in the first place to buy one) is going to be what type of conservatory to have. There are so many types to choose from. You could strat your search here: https://www.localconservatoryprices.co.uk/how-much-does-a-modern-conservatory-cost/
The most popular types of modern conservatories are:
These 3 are not the cheapest type of conservatory in the market, but each has really great features that make them very contemporary.
You could of course go for a regular Lean-to or Victorian, even a Georgian or Edwardian style. But if you want to be bang up-to-date, then a Loggia or Glass framed conservatory could be the one for you.
Check them out at https://www.localconservatoryprices.co.uk/