Here's the 'bean bag' that I got. It's actually a memory foam one and is about four feet in diameter. It is on the pricier end ($100-ish w/ delivery), but I got this my freshman year and absolutely loved it. It fit perfectly in my dorm room and my friends really like it too. If you're shorter than 6', you can curl onto it and fit your whole body, or it's big enough to sit two people comfortably.

Some things I would caution about is that it is heavier than it looks and would probably require two people to carry it more than a couple of meters. Washing the cover is a pain (coz there's no inner bag, just foam pieces). Storing/transporting it could be a little tricky coz of how big it is.

That's my two cents. I think the bean bag is definitely worth it (and would have been moreso if I didn't have to go away from campus for a year), but if you're someone who likes lounging on a place that's between a soft mattress and a sturdy chair, this could be worth it. Would recommend checking out other foam bean bags too.