Budget travel in Sri Lanka has a specific window problem that's worth understanding before you plan.

The island has two monsoon seasons affecting different coasts. The southwest coast (Unawatuna, Galle, Mirissa) is ideal October-April. The east coast (Trincomalee, Arugam Bay) is ideal May-October. Traveling in the wrong season means rain, rough seas, and some accommodation closing.

Once you're in the right season and coast: Sri Lanka is genuinely affordable. A good guesthouse room (private, air conditioning, breakfast included) runs $18-30/night. Tuk-tuks are the primary local transport and can be negotiated for day rates at about $25-35 for a full day of driving including a driver who waits while you visit sites.

Food: the rice and curry culture is extraordinary and cheap. A full rice and curry plate with multiple curries, papadam, and sambols costs $2-4 from a local restaurant. Hoppers (bowl-shaped fermented crepes, sometimes with an egg inside) are one of the great budget breakfasts anywhere in Asia at $0.50-1 each.

The wildlife safaris: Yala National Park is famous for leopard sightings. A privately booked jeep (arranged through your guesthouse) for the morning session costs $40-60 shared. Do not book through the park entrance with the touts — they charge more and the jeeps they assign are lower quality.