If only it were that easy it would be great but it simply isnt the case that some of those that charge over £150 an hour have a bad attitude. Alex ex of the Bunny Lounge was £180 an hour and now an Indie charging similar is highly regarded as was the pornstar Keira Pharrell who also charged me £180 an hour. Natasha and Kitty of this forum i think both charge over £150 an hour now and are both very highly regarded as well.
As ever it depends on the individual WG as to what her attitude is, what she charges is not the defining factor, if good she will be good at whatever price she charges as shown by Paris ex of Soho Walk-Ups who was very highly rated yet a very cheap costing punt. And Katie Weale who charges around £200 an hour isnt worth 2p an hour in my experience being an horrendous WG.
My advice is always look for VFM and yes there are very many good WGs about from £100-140 an hour with my normal maximum being £150 an hour but as above i will break that for a WG i fancy and rate enough. For me to go over £200 an hour nowadays the WG would have to tick all my boxes and none have so far appealed enough for me to do so. Above £200 an hour i can see known pornstars who can charge a premium getting punters interested in them but apart from that for me its ridiculous money. 
I saw this on a WG's blog recently ( although it was removed after only o few hours on there ) and thought it a humorous take on this subject, so here it is:-
ONE PUNTER'S VIEW
Working Girls or Prostitutes, What is in a name, There are no decent substitutes, But they're not all the same
Posh Totty through to cheaper ones, The price is no good measure, I always find the FRIENDLY ones, Give me the greater pleasure
Experience and friendliness, Is that to much to ask, And a little supple bendiness, As they go about their task
It often seems the actual thing, Can mean a little more, If we have heard our laughter ring, In the minutes just before
So try meet us looking smart, And greet us with a smile, A chat, a joke, before we start, That really has more style
We're more likely to return to you, To have another punt, If we can find some more to you, Than just another C___ !
