It depends on where you live. There are community centers in areas such as Maryland Heights that have indoor pools or you can check out Shaw Park pool in Clayton. You can go to the Y but you will have to pay a membership. Some school districts use the high school pools for residents of the district at various times for low fees. There are recreation centers in north and south county run by St. Louis county which are reasonable. You can also join a private club such as the Lodge at DesPeres.
I know the girls in Pop s and P.T. s charge quite a few bucks for a lap dance in East St. Louis, but I m not sure what the going rate is.
YMCA or YWCA, Gold GYM
I m not sure. . . sorry :/