Welcome to the forum!
As culzean says, it's a fair bet that the caliper slide pins need stripping and lubricating, and any decent independent should be able to deal with that at minimal cost.
I would avoid the big garage chains such as Halfords, Kwikfit, etc., they try to charge near franchised dealer prices for work, and only fit cheap pattern parts anyway. I bought our first Jazz with a box file full of receipts, mainly for work done at these types of garages. Some of the Halfords invoices for brakes were more expensive than the franchised dealer fixed price offers.
Honda franchised dealers offer fixed price repairs for common work, and the current price list is on the website - for example, rear discs and pads will cost you £317 all in. List price for an OEM rear caliper is an eye-watering £477.45+VAT, and that's without the £100/hr labour
A decent independent is usually the cheapest option. They will normally use a local motor factor for parts, and you are probably looking no more than £150 for factor parts, including one replacement (pattern) caliper, if needed. Add a few pounds for sundry items, plus a couple of hours labour at around £40/hour, and I would guess my MOT man would charge under £250 for the whole job.