This isn't a tuk-tuk in Bangkok, taking you to a gem tout or running up the fare.
I recall World having a sedan service/designated cab that you can use- €65 (so $80-ish one way from Frankfurt at today's exchange rates). You can probably call them for that (on their website).
As you can see, the bill's going to add up. IMO the cab is not that hard to handle for Oase, FKK Samya, and Living Room (as long as you find a place to stay close by, and if you don't a train to a place where you can grab a cab is fairly easy).