You want a handheld gaming PC that can actually handle your favorite games on long flights and hotel stays without falling apart after six months. Getting the right model means you buy it once and keep it for years, rather than upgrading next season because the battery life or thumbsticks let you down.
Watch the release cycles closely because when a newer version drops, last year's model usually gets a price cut or a steady supply of refurbished restocks. That is the sweet spot for value, especially if you line it up with the summer digital storefront sales.
Remember that the 18 months is a hard deadline and not free money. If you still have a balance left when the intro period ends, you will get hit with interest on the full starting amount from day one.