I agree with letiole. Wayan is a fabulous driver. He knows where to go, both in terms of major tourist attractions and quiet side roads. He knows the island thoroughly, and can knows where to take you for any activity that appeals, whether it is hiking, shopping, eating, sightseeing, or beaches.

Wayan lives outside Ubud. If you were staying in Ubud, his rate would be less. But he has a two hour drive to the south of the island, and two hours back - so it is an issue of time and gas (as letiole has mentioned).