We paid £40 per hour for 1:1, but that also included setting/marking homework outside that hour (so more like 1 1/2 hours of actual work/time), and the lessons were in a hired room in a church hall, so probably £5-£10 of the £40 would have been room hire costs. But he was excellent and well worth it. He created his own worksheets/materials, rather than using published books/papers, tailored to the two grammar schools so it was all very specific.
We only used him for an hour per fortnight for the few months before the 11+. Although we know others who used him for 1 or 2 years which was more the norm. It was more for exam technique etc rather than anything else for our son, which is why the tutor was happy to fit him in for the last term or so only.
About a month before the 11+, he hired a church hall and turned it into a "mock" exam for a full Saturday morning, which exam style tables etc., and gave all his students a proper mock test with his own exam papers. He made it as realistic as possible. Must have been 30 or 40 kids there. That, again, was well worth the money as primary kids just don't experience "proper" exams, so it really helped them to get the feel for what the real thing was going to be like.
It took us a while to find someone suitable as this guy didn't advertise. We spoke to a couple of others but they sounded very "wishy washy" and vague, and we weren't impressed. This guy was old school, quite abrupt and to the point and gave us a lot more confidence. My son responds far better to a relatively strict and no nonsense approach so it turned out a good match.