With the Open University, you can pay course fees in instalments (typically about £700 over the course of a year -- may be a little more for overseas students). I don't know if that's within your means or not.
This is distance learning BTW, not university proper. All coursework is submitted over the internet and you have a tutor that you can e-mail to your heart's content -- you also have unlimited access to academic journals/articles through online services like Jstor etc.
See www.open.ac.uk for more info. You might also look for a US equivalent which might save you a bit of money.