I've used Shipley a few times https://www.shiply.com/lp/land/delivery?utm_source=google&utm_medium=cpc-brand&utm_campaign=Shipley. 90% of quotes will be very expensive, but on occasion you get lucky because one of the drivers bidding for the job happens to be doing the journey anyway, or looks at it and plans another visit at the same time (I had a guy deliver a bass to me from Hampshire who did it cheap because he was able to combine the journey with a visit to relatives). In my experience, if you wait around for a couple of days eventually a cheap quote lands for one reason or another. This is really useful if the item is hard to pack, or too large for a commercial courier etc (I had my 3m x 2m heavy studio desk delivered for £90, a commercial courier simply wouldn't have touched it, in part because the two Shipley guys had to go into the studio from where I bought it and carry it down a few flights of stairs). I also had a large number of used acoustic tiles delivered for virtually nothing, again, a commercial courier would have charged a fortune on account of the 'volumetric weight' (they weighed a couple of kgs but were about 2m x 2m x 2m).
I will say that on the whole I still use Interparcel, and with a couple of exceptions - such as their recent failed attempt to charge me for alleged poor packing - prices are still good, and service times especially with TNT are still good. My major issues with couriers recently have been with incoming stuff that I've bought, often commercially as opposed to privately, but also with a couple of things I bought on here (including a rather badly mauled Mesa head). On more than one occasion with private sales the damage has been the result of the packaging being nothing like up to the task; a frequent disaster is people assuming it's OK to send a heavy item using the sort of rigid foam packaging that is used to protect flatpack furniture in very tightly and precisely engineered boxes, but which simply explodes into a thousand small polystyrene balls the moment it receives any impact in a box that it wasn't designed to fit. This, I guess, is a significant part of the reason that couriers make people pay for insurance, because so many people's packaging is complete pants