Budget beach travel gets expensive fast if you follow the default tourist infrastructure. Here is how to approach it differently.

The problem with popular beach destinations: the accommodation built for tourists is uniformly more expensive than inland accommodation. Koh Phi Phi in Thailand has beautiful beaches and uniformly expensive everything because the island has a captive audience with no alternative.

The strategy that works: identify the ferry or boat connection point that's less popular. For Koh Phi Phi, the island of Koh Lanta is 40 minutes by ferry, equally beautiful, and costs 60% less for equivalent accommodation. For Santorini, the island of Naxos is a short ferry hop, far less visited, has better beaches, and a guesthouse that costs €50/night in Santorini costs €25/night in Naxos.

The research method: on any map, look at the islands and coastal towns adjacent to the famous one. Find the ferry connection. Check accommodation prices on Booking.com. The famous destination will usually have the highest prices in the cluster and the surrounding options will be meaningfully cheaper with comparable or better natural settings.

Also consider: timing. The Greek islands in June and September are 40-60% cheaper than July-August and the weather is excellent. Southeast Asian beaches in shoulder season (May, October) are 30-50% cheaper than peak with the same water temperature.