Recently I was discussing here the similarities between prostitution and casual sex, and i received the argument that it's the cash transaction in prostitution that sets it apart and makes it worse than casual sex.

But, if you consider Tinder, Tinder charges subscribers differently based on an algorithm where users can be charged five times as much, depending on gender and age:

https://foundation.mozilla.org/en/blog/new-research-tinders-opaque-unfair-pricing-algorithm-can-charge-users-up-to-five-times-more-for-same-service/

So Tinder is a platform where "buyers" substitute "sellers" their access to the platform.

In the instance of using Tinder for casual sex, how is this remarkably different to prostitution in terms of its cash transactional nature?

Is it really that different?