You don't pay a yearly maintenance for any of them because if they break, you're going to have to fix them yourself.
Most companies prefer to actually have a support plan, because if they don't, the alternative is to pay their own people to fix them, and it's usually cheaper to not pay someone full-time to have expertise in that area.
We had hundreds of expensive Macs at my last gig. Guess how many of those we bought AppleCare for? Zero. This was also true of pretty much every piece of electronic equipment we owned.
Note that this isn't very unusual either at most companies. Given the low failure rate of most electronics, it is simply cheaper for the business/IT team to buy a replacement Mac / router / whatever than to pay any kind of yearly maintenance fee, which is always designed to make more money for the vendor.
$250/year for a $999 piece of equipment is not a good deal. If it were an option, like AppleCare, most would advise you to not take it.