Overview
Thailand is one of the most affordable charter destinations in the world. Charter rates are competitive, and on-the-ground costs — food, fuel, marina fees — are a fraction of Mediterranean or Caribbean prices.
Charter rates
A bareboat catamaran in high season runs $4,000–$8,000 per week depending on size and age. Monohulls are cheaper at $3,000–$5,000. A skipper adds around $1,100 per week, and a full crew (skipper plus cook) roughly $2,600.

Running costs
Expect food and provisioning around $40 per person per day — far cheaper than Europe, with excellent fresh markets. Marina fees average $35 per night, fuel for a week of gentle cruising around $250–$350, and national park fees apply in some areas.
Sample weekly budget
For 6 people on a bareboat catamaran for a week: charter $6,000, food $1,680, marina $245, fuel $300 — roughly $8,225 total, or about $1,370 per person. Add a skipper for ~$185 per person.