When you're ready you can do it when you want. You don't have the overhead that a relationship comes with. You get someone who's experienced and a lot less inhibited. Many very successful men who can get sex for free still call escorts. There really is no such thing as free sex.
Free sex comes with a price.
There's always the issue of where the relationship is going. Dealing with her friends and family, her habits, spending quality time together, being obligated to do things together. Not that there's anything wrong with that if you want that. But if you just want to get laid, everything else make that free sex very expensive. Let's face it.