By the time you're ready to put it down for a season or two you'll have gotten your money's worth many times over. If any of that sounds interesting then for the $20 or whatever it takes to get RoS on sale it's just an insane value. It's equally enjoyable solo or multiplayer. You can play the original Diablo 3 without the expansion however and buy the expansion later. Consoles have The Ultimate Evil edition, which includes both the base game and the expansion. Reaper of Souls is just an expansion and doesn't include the base game. It's beautifully designed and has A+ music and sound and the characters are all satisfyingly thwunk-y to play. Yes, you need to buy both, unless it's for a console. D3 is very much a sustained arcade game: drop in, smash shit, get shit, exit. Ultimately the game's long-term value is in the grind, incrementally beefing up your characters and getting that fresh dopamine hit when the right item drops, so if that isn't for you then I'd say don't bother with the game at all - as fantasy RPGs go it stinks, go with something from The Elder Scrolls or The Witcher series. It's more like an endlessly rolling, three-month feeding frenzy with well-populated multiplayer games and opportunities to get unique rewards (mainly extra stash tabs, i.e. I can see why you might think the seasonal concept sounds weak at a glance, but because everything you do in-season rolls into your non-seasonal profile when the season ends it's not like it's a wasted effort. RoS "only" adds a single Act (chapter), bringing the total from four to five, but with Adventure Mode it turns the game into an endless slot-machine arcade. Vanilla D3, the original base campaign, is short and isn't very memorable.