Do you have a lot of domains? If so, then why not join Nominet? There's the initial joining cost and yearly membership fee to offset, but then it's trade price for everything AND you control everything, no 3rd party to screw things up.
If it's just a few, then I can't help as I've had membership for so long that I've no idea what the retail prices are, but there should be a raft of recommendations along soon.