Casio M5610U with a metal mod I picked up for $99 and I love it! Pick up and go with never a care for durability or accuracy. World time across 5 presets, that you can swap back and forth with your home time at a press of buttons, solar powered, and radio receiving for auto updating of time and date.
What's your cheapest watch in your collection?
Cheapest would be the GA2100 based Casioak I built myself (replaced the case/bracelet, dial, hands, chapter ring and index).
https://preview.redd.it/fgl2dfvdx9wb1.jpeg?width=2565&format=pjpg&auto=webp&s=9e9ce97646f13883f8b597fe944309757e87ae53