Hmmm. Timely for me, having just negotiated a sale that requires 3 parcels each of moderate dimensions but weighing nearly 10kg.
I thought I would start looking at prices.
Royal Mail / Parcel Force: easy – just look up the tables.
Hermes? They assume asking the price is booking the service, and want to know all the details when you all need at the start is the fee for a parcel of X by Y by Z cms (obviously not engineers) and so-many kg, of contents of stated value and not in a remarkably long exclusions list. It looks too as if you need use their convoluted process for each box, not treat it as one consignment of 3 boxes.
I am almost tempted to verify just what long-distance driving we are allowed to do now (about 200 miles each way)…
I think I will plump for Royal Mail.