Typically one-way fares are 300-400B. Depending on peak or off-peak seasons, the price might be negotiable. Many hotels or resorts in the Laguna area will provide a shuttle bus.
It might be a good idea to organise to see a Muay Thai boxing match which usually includes a pick up from hotel and then ask to be dropped off in Patong to continue partying. You would really only go to Patong at night since that is where all the nightclubs, bars and bustling restaurants are. In the daytime, you can certainly better off at your own beach on the good side of Phuket. Swimming at Patong beach, gave me a rash, so I would avoid it if possible.
Safe travels! :) about 7 years ago