Taking Taxi meter, or any other Taxi in Samui is nothing like Bangkok. Taxi meter do not operate the meters, you need to bargain and agree on a price prior to getting in and it will end up expensive for Thailand standards.
The worst is taxi to and from the Airport, it can cost 400THB for a ride of less then 6km or 10 min. The best advice get transfer from your hotel or even better, get the Limonene Service from Bangkok Airways after arrival. It is not real Limonene, just a nice and safe minivan at very resnoble price 100THB to most destinations. Some agencies on line like Tours Koh Samui can even arrange any transfer ahead of time for good prices.