Several comments:
First, if the only thing you are using the computer for is Internet-related stuff, then 256 RAM is OK with Windows XP. Since the Internet is usually so much slower than the computer, the only major difference most people will notice is that bootup takes longer. I've used XP with as little as 125 RAM, and its been fine once bootup was completed. (if you want to get into creating movies and such like, then its a different story.)
Next comment: if you get your own computer, then you have to also think about Internet security, so that it does not instantly get gummed up with viruses and such. If you don't know about this subject, then plan on facing a MAJOR learning curve.
I can suggest some good sites for learning about it if you want.
Finally: as an alternative if money is an issue: have you considered getting a flash drive (cost: about $10 USD for 1 GB), and setting it up with browser, email program and such like. This can then be plugged into any PC computer, anywhere (e.g Internet cafes, public libraries, computer clubs), and in effect, that computer becomes YOUR computer. Plus the host computer can handle most of the security issues, which is easier for you.
Worth a thought?
