Here is the thing, make sure you like ARPGs first before investing in any ARPG.
If you have to ask what ARPGs are, then Path of Exile is definitely not the game for you to even a small degree. Don't misunderstand, Path of Exile is currently [with the exception of Diablo 2] the finest designed ARPG of all time.
Path of Exile is most definitely not casual friendly or "new to the genre" friendly at all. In fact, the game is designed intentionally to not be so. By design. By design the developers made a purposefully difficult, obtuse, high grind, high commitment game. That was their intention and they nailed it pretty much dead on.
If you are new to ARPGs and don't yet know if you like the genre long ter; Torchlight 2.
Firstly, Torchlight 2 is just a mere $20. Often cheaper as the games is on sale often for $10. I believe it is cheaper still for multiple copies.
Secondly, Torchlight 2 is a very simplistic ARPG that gives you the basics of what the genre is about in essence. So one would likely walk away with a firem idea of what other ARPGs are like in basic gameplay; point & click, loot farm, never-ending.
Diablo 3 is $60 and little lengthier than TL2. In cost efficiency here TL2 is a better bet for a newish person.