We took a taxi van for ~6. Was fairly quick and the price wasn't bad. If you want to be sneaky just book some Scuba off the coast around Pearl, that's where their dive shop is. We turned that into a day trip at the resort
We just did the erotic massage at Pearl and it was incredible. We used USA Transfer it was a 50 min ride from TTR to Pearl. I would think if you took a bus the travel time would turn into a all day event. Might want to see if you can add a day at the resort of see if they will allow you to switch a day. Tell them your thinking of becoming Premier and want to try the other resort before you make a decision. They might be more flexible
I just contacted USA Transfers because we need a ride from Desire Rivera maya to Temptation in November. I was told it was 45.00 for a private one way ride.