I think of it as offering a relaxing service, having a great outfit, makeup well done, taking wardrobe requests, not being rushed especially if the client is late, don't be booked back to back, etc.
Treating every client as if they are the only one that matters during your date.

Yes, I think high end is the experience, not the rate.

BB

I definitely agree with comments that it is not about the rate, it is about the person. How she can make you feel while together, makes you forget that she is not really your lover. She is always sexy, passionate, well rested and personalizes every moment with you. She makes her focus YOU. She is well read, intelligent, she can talk about topics that are fun and frivolous to deep and intellectual. From politics and world events to silly stuff like what is the hottest movie out. She takes time to truly get to know your interests, and is genuine about her interest in that as well.

She can be taken to a black tie event and can mingle and socialize and discuss topics right along with the rest never to raise a eyebrow. Then she can go back to your room and turn into the naughtiest, and sluttiest play thing.

She generally only sees maybe one or two men a week, as much of the higher end women have a full time career, or schedule and this is very part time for her.

She is ALWAYS manicured, and fresh when you meet. She gets spa treatments regularly and works out to keep in good shape for her body size (as not all women can nor want to be thin or skinny, some have
great toned but curvier bodies and want to keep that look )

She wears very flattering and sexy but not revealing clothing, again to never raise a eyebrow, but turn heads.

This to me epitomizes HIGH end. It is not about the rate. however women who do the above, WILL be at a higher rate structure, because they cater to a SPECIFIC type of gentleman.

many woman who think they are beautiful and can pass as high end, can not. Just beauty alone is not enough.  
this is truly just my opinion.... but...