Rent only to explore the set pieces of Lost. Even doing this is practically a waste of money.
You really know there is a problem when you've played a fan-made CounterStrike Source mod of the Lost island that allows you to do more in the Swan Station than what you do in the entire game of Lost Via Domus. In the mod version of Lost, not only can you play music from the record player, take an AK 47 from the armory, you can also watch all the stuff in the Swan get sucked towards the electromagnetic thingy when you don't enter the numbers and see a blue sky event. In the official Lost game, made by an actual company with an actual budget, the Swan is a static set piece with nothing to do but a puzzle that appears over and over again throughout the short and quest-for-easy-money game. If you don't enter the numbers, instead the screen blacks out. No cool display of physics as stuff goes flying across the room, nothing.
Moving onto gameplay. Via Domus is very simple. You pretty much run around going from point A to point B. There are a couple of rare points in the game where you can shoot people, but it's rare.
I don't think this game deserves anymore time. I'll finish by saying that the only point of the game is to get your fix of Lost set piece ejaculate.
I don't recommend touching this game unless you get it for free somehow. Even then, it's probably better not to waste your time and just watch the show.