I’d be happy to help plan a 30-day trip to Thailand on a budget! Here’s a sample itinerary:

Day 1-3: Arrive in Bangkok, check into budget accommodation (cost: around $10-15 per night)
- Travel method: Fly into Bangkok’s Suvarnabhumi Airport, then take the Airport Rail Link or a taxi to your hotel (cost: around $1-2 for the Airport Rail Link, or $10-15 for a taxi)
- Activities: Visit the Grand Palace, Wat Phra Kaew, Wat Arun, Wat Pho, and explore the city.
Day 4-6: Take a bus or train to Chiang Mai
- Travel method: Take a bus or train from Bangkok to Chiang Mai (cost: around $20-25 per person)
- Activities: Visit the Chiang Mai Old City, Wat Chedi Luang, Wat Phra Singh, and take a cooking class or a Thai massage class.
Day 7-9: Take a flight or bus to Chiang Rai
- Travel method: Take a flight or bus from Chiang Mai to Chiang Rai (cost: around $30-40 per person)
- Activities: Visit the White Temple, Black House, and take a day trip to the Golden Triangle.
Day 10-12: Take a bus or train to Phuket
- Travel method: Take a bus or train from Chiang Rai to Phuket (cost: around $20-25 per person)
- Activities: Visit the Phang Nga Bay National Park, James Bond Island, and the Similan Islands.
Day 13-15: Take a bus or minivan to Krabi
- Travel method: Take a bus or minivan from Phuket to Krabi (cost: around $10-15 per person)
- Activities: Visit the Railay Beach, Tiger Cave Temple, and take a boat tour to the nearby islands.
Day 16-18: Take a bus or minivan to Koh Samui
- Travel method: Take a bus or minivan from Krabi to Koh Samui (cost: around $20-25 per person)
- Activities: Visit the Big Buddha statue, take a Thai massage class, and visit the Hin Lad waterfall.
Day 19-21: Take a flight or ferry to Koh Phangan
- Travel method: Take a flight or ferry from Koh Samui to Koh Phangan (cost: around $30-40 per person)
- Activities: Visit the Than Sadet Waterfall, take a yoga class, and attend the Full Moon party.
Day 22-24: Take a ferry or speedboat to Koh Tao
- Travel method: Take a ferry or speedboat from Koh Phangan to Koh Tao (cost: around $20-25 per person)
- Activities: Visit the Shark Bay, Mae Haad Beach, and take a diving or snorkeling trip.
Day 25-27: Take a flight or ferry to Pattaya
- Travel method: Take a flight or ferry from Koh Tao to Pattaya (cost: around $30-40 per person)
- Activities: Visit Pattaya beach, the Sanctuary of Truth, and take a day trip to Koh Larn.
Day 28-30: Return to Bangkok
- Travel method: Take a bus or minivan from Pattaya to Bangkok (cost: around $10-15 per person)
- Activities: Visit the Wat Mangkon Kamalawat, the Wat Ratchabophit Sathit Maha Simaram, and do some last-minute shopping.
Note: This is a sample itinerary and can be adjusted to your preferences. Prices and activities may vary depending on the season, please check the current situation before planning your trip. Also, please note that the cost of accommodation, food, and other personal expenses are not included in this budget. Some additional activities you could consider are visiting the Pattaya Park Tower, the Pattaya Underwater World, or taking a Thai cooking class. It’s important to book accommodations and transportation ahead of time as it can save you money and also make sure you have a place to stay. Also, It is important to note that getting around Thailand can be cheaper by using local transportation such as buses and trains instead of flying.