Wouldn't really recommend the "State" coz it's really localized. It's style like whore houses in Hatyai/Danok. But for those who insist you can take the BTS there.
Lumphini Park FLs can be had as low as Bht600 a pop. Health of sex workers who are usually past prime or who have STDs that can't work in regular chiong joints. Lumphini IMHO is a rung lower in the FL street pick ups than Old Siam hotel, now along the railway line that runs behind. Nana Hotel carpark full of fugly MILFs or katoey's your kind of thing if u r into fucking fudge tunnels or ugly women.
Best juz stick to tried and tested Nana, Soi Cowboy, Patpong, Saphan Kwai, massage shops at Rachada, Sukhumvit and assorted kapoo joints. If wanna try FLs then Tharmae or after hour clubs like Insanity, Scratch Dog or Mixx my preferred hunting grounds.
Good luck everyone!