There are a few reasons to see an HDH. Only a few of them I agree with.
The one thing that you "should" expect from a woman with a higher rate is a better ambience, better hotel, nicer sheets, snacks, drinks etc. If those things are important to you than yes a woman with a higher rate can be justified just like a person can justify paying five times the price for a first class ticket over coach.
Another reason is if money simply is not that important to you and a certain woman is just a "must see" in your book. If a woman REALLY appeals to you, do you want to deprive yourself of the experience over a few hundred bucks?
Now there are some really dumb reasons to see a HDH as well, some of them include a mistaken belief that "you get what you pay for" That is simply not the case where it comes to providers, Not all HDH's are hot, some of them are rather average looking or even homely IMHO, and there is only so many ways to actually fuck and a thousand dollar hooker can't fuck any better than a three hundred dollar hooker.
Personally, unless I am traveling to a high dollar city like NYC or LV where the "going rate" is more like $500 hr than the $300 hr rate that is the norm in my part of the country I almost never spend more than $3-350 hr when at home. It's not a matter of being cheap, it's just that there are so many great women at the price point there is simply no reason for me to pay more.