Three main things to consider:
Getting family to accept it
Working out where we'd put the tank
Working out how much it would cost to run/feed
The acceptance is the biggest problem and something which I honestly don't think will work. My sister in particular suffers from arachnophobia and doesn't like anything with 8 legs (cause I asked her what she thought about octopuses) and chances are she'd have too many nightmares if I got one.
However, I am on the lookout for a job now and once I start bringing cash in, there is a *chance* my parents would consider it, though to be honest I think my mum and sister's rection would be along the lines of "no way, theres no way" etc.
Funnily enough, I had/still have a fear of octopuses cause with all their legs they do remind me of spiders (and I hate spiders) and I have gone to aquarium's before and felt quite intimidated when Ive seen an octopus attatched to the side of the tank with its legs spread (so you get a similar view as to what its prey does before it gets eaten), I also didn't particularly like the way it pounced on its prey because I know if I were under its tenticles at that time it would scare the crap out of me.
*But* all of that is changing. I am beginning to see that octopuses aren't so bad. That they are not the man eating creatures several movies have made them out to be. Sure they pounce on their food in a way that makes me shudder.......but I have two cats and they are one of the animals which are renound for their pouncing and ripping things to shreds. Plus the interaction Ive read about with the octopuses (e.g. reading stories which would make you reconsider if a dog really is man's best friend) has made me think clearer about them.
So part of the experience in wanting a pet octo is about getting over my fear. I know some of you might reply that the octo could also be used to help my sister get over her fear, but my sister has learning/understanding difficulties so it would be very hard (if not impossible).
Anyway, Im babbling on.......