It really depends on what kind of experience you want. If it is a physical release, then a shorter time is fine, but how much connection is there?
2-hours really isn't a long-time if you are wanting more of a girl-friend or lover experience, which courtesans offering longer timeframes can offer. It is so much more than the physical act itself. It is also an experience of the mind, that with a good courtesan takes the experience to a much higher level. There is a depth of connection and feeling that you are the most important man in the world to them... right at that moment. There is a connection, wisdom gained from their experience, and skill that they use. It feels natural and something that makes you feel fulfilled. It is a creation of a fantasy of something we are unable to find in our normal life. And in the process the lady may also be a confidant, a counsellor or psychologist, a friend, a muse, as well as a lover. There is so much more depth... and it has healing powers as well. I know some ladies consider themselves to be healers, who truly understand the needs of a man and how their psyche ticks. There are a number of ladies in this profession who started off as nurses. They continue to be healers, but in a much more satisfying and lucrative way.
If there is a language barrier, or a lack of experience, it is less likely that longer time periods are worth the money. But where the lady knows what she is doing, there is considerable healing that can happen from the encounter. Sex can be much more than just a physical act, and longer appointments can allow for much more depth in the experience.
Not for everyone, and yes, you need a deep pocket to do this.