Coin-op machines (6.5 Kg - 12 Kg) in my neighborhood are 40 baht, the dryers are 10 baht/15 minutes, so a single load is ~ 80 baht. The fixed costs are ~ 40 baht, my guess (depreciation, water, electricity). In Thai neighborhoods machines are 20/30 baht, but typically no dryer while laundries sometimes charge by the piece, for larger items like bedding/towels, or by the kilo for smaller items.