While OEM remote car starters are relatively new, these devices have been available through the aftermarket for a long time. Often paired with car alarms, keyless entry systems, and other similar devices, they are also available as standalone units.
When you buy a new car that comes with a remote starter, the cost is usually buried somewhere in the fine print. Compared to the cost of everything else, it usually isn't that big a deal.
Aftermarket remote car starters aren't that expensive, relatively speaking, but there are two associated costs to take into account: the price of the remote start kit and the cost of installation. While it's possible to find a basic remote starter online for under $100, that's just the install kit. And the fact is that installing a remote car starter can be a pretty complicated job, especially if your car has built-in anti-theft measures.