Well it's funny you're willing to pay 15$ a month or the equivelant when it only costs 15$ a month for DSL.... LOL!
56k isn't even worth having REGULAR internet! My friend has it and he HATES it. Games will barely even play!
I can only say I know how you feel because there were the days when my family had AOL 4.0 Then we tried to cancel it for DSL and after like a week AOL finally gave up on us.
Anyways, I would use 15$ a month firstly for DSL before you do anything else.
The chain goes like this:
Save money until you can get an OS.
Save money until you can get DSL.
Then you're good to go!