I rented mine like 570baht~ a day. So i think that yours had a fee of some sort.

You can rent through hertz at the Phuket airport. Minimum of 5 days rental, so you wont have to pay the fee to drop it off at a different location. I paid about $120~ for 5 days at Phuket airport on July 28th, dropped it off at Suvarnabhumi 5 days later. The drive was fine but I passed 5 checkpoints on the interprovincial borders along the way to Bangkok. Just make sure you got an international driver’s permit and they will let you pass easily. Good luck! 🍀