Did budget Langkawi a few times, here is the playbook. Flights: book early and go on weekdays, and set fare alerts, prices swing wildly. Alternatively take the ferry from Kuala Kedah/Kuala Perlis if you drive up north first, can be cheaper for a group. Langkawi is duty free, so ONE big win is buying groceries, snacks, and drinks cheap there, and chocolates/things to bring back. Stay: skip the beachfront resorts, get a guesthouse or Airbnb slightly inland near Pantai Cenang, walkable to beach but half the price. Food: eat where locals eat, the warung and Cenang night spots, avoid the fancy beachfront restaurants that mark up for view. Cheap/free stuff: the beaches are free obviously, Cenang sunset is gorgeous and costs nothing, Eagle Square, and the cable car/skybridge is worth the one splurge for the view. Rent a motorbike or small car cheaply to explore instead of taxis which add up. Also duty free alcohol if you drink. A couple can do a decent 3D2N well under budget if you avoid the resort trap.