The economics can vary based on the film and where you buy it. In other words, some films and vendors have a much lower cost per frame with bulk versus 36 exp cassettes. You have to assume a limited life for cassettes if you want to avoid possible scratches (depends on how you use them and how much risk you're willing to accept). Bulk loaders (as noted above) are cheap on the used market - at least in the US.
As to storage, I don't see a lot of difference. Certainly, long term storage of a bulk roll is more compact. But if you load the full bulk roll storage savings is moot. And if you store the roll in the bulk loader then it's less compact. You could load and unload your bulk roll into the loader, but then it's a lot of freeze/unfreeze cycles.
What I really like about bulk loading is the opportunity to load short rolls (i.e. 12 exp).