On both islands you can make it as expensive or as cheap as you want but the prices on Koh Samui for accommodation and food are slightly higher than on Phuket. Both islands are a lot more expensive compared to Bangkok.

In 2026, Phuket is generally considered more expensive than Koh Samui for a high-end or luxury lifestyle, but the comparison depends on your specific travel style. According to cost-of-living data, Phuket's overall expenses are roughly 16% higher than Koh Samui's, particularly in the sectors of real estate and fine dining. Phuket’s status as a mature, world-class hub means it hosts more Michelin-recognized restaurants and ultra-luxury villas that can command prices far exceeding those on the smaller island. However, transportation is often where the roles reverse; Koh Samui’s airport is privately owned by Bangkok Airways, leading to higher flight prices and a "monopoly" on direct connections that can make getting to the island more costly than flying into Phuket’s massive international airport. While Phuket has a more diverse and expensive "cosmopolitan" buzz with its extensive beach club scene, Koh Samui often offers better "value for money" for families looking for beachfront villas and a more tranquil, wellness-focused environment.