I would not take the job.
I'm currently 21 and although have had no "real" job, i've been self employed while at university and been fortunate enough to get a few "Good looking" contracts out of the way.
By the sounds of it, you've got the skills to fund yourself through your degree. You should get a BSc under your belt and also enjoy the social side of it all - the degree will open more doors for you, which no one can deny. Even if its a route that you don't wish to consider now, a degree in Computer Science will let you into roles in large scale firms, where starting salaries typically exceed what you've been offered. As others have suggested, work experience is very important. However you can achieve both by possibly negotiating part time work (or a placement / internship) with the same employer or even with someone else.
That said if you're as talented as you suggest, there is nothing to say that you wouldn't be successful without a degree. However in my honest opinion, if you're sitting on a 1st now and have just two years left, you may as well finish it.
I am of course a little biased - just graduated in Computer Science.