I'm sure there are a few that offer Greek. Some escorts offer Greek, and charge more than regular vaginal sex. And if your cock is bigger than a certain size they may want even more money. Is it worth it? Depends if you just want to try it out to see if you like it.
Another thing, you have to be careful when having Greek. Condoms break much easier when having Greek compared to vaginal sex. So, if you want to save your health and a few dollars, I'd say stick with vaginal sex instead. Most women have pussies that feel reasonably good, unless they're constantly playing with big huge dildos.