We would only recommend buying your shutters online if you have (or know somebody that has) the required measuring and fitting skills to carry out this task. Most windows aren't perfectly aligned which means you may have different measurements at the bottom, middle and top so if the numbers are wrongly taken you will certainly have a problem on installation day.
Measure and fit costs will vary between £140 - £300 depending on the amount of windows you require shutters for.
If you'd like to understand the whole process more in depth, we would be more than happy to have a chat. You can call us on 020 8871 9222 or visit us at plantation-shutters.co.uk
W hope the above helps.
Plantation Shutters Ltd Team.