Not necessarily. Having both a short legal ceremony to cover those aspects as well as a celebration led by an Independent Celebrant need not cost much more, and in some cases may even be less expensive. Ceremonies at the Register Office are cheaper during the week than at weekends. If the two ceremonies are separate there is no reason why the legally recognised one could not take place on one of the cheaper days, even if it is a different day to the main wedding ceremony.
Hotels and other venues that are approved premises for weddings usually charge more just for offering this option, whereas you can have the main event at any venue if the legal aspects have been covered elsewhere, bringing costs down.
For example, the cost of a Registrar-led ceremony at one of the Register Offices in Kent or Bexley* are as follows:
from £225 to £800 Monday – Friday
from £390 to £1,070 Weekends and Bank Holidays
Prices vary according to venue, the cheapest venue holds a maximum of 16 guests, the dearest up to 85.
For a Registrar to lead a ceremony at an approved premises, the costs are:
£565 Monday to Friday
£745 Weekends and Bank Holidays
This does not include any fees charged by the venue.
By contrast, the combination of the simplest legal ceremony at £46 (available weekdays only) combined with a ceremony led by me could be a more cost-effective option, and give you a personalised, tailored and flexible ceremony that exactly meets your needs, without the restrictions of time or venue.
*information from KCC website for ceremonies taking place 1st April 2018 – 31st March 2021 and excludes the cost of giving notice.