All these things that I have done

Nearly gave myself a heart attack just now. I was just doing a quick budget estimate for the rest of the month, trying to decide whether I could afford a second hand computer (only £650 - it would be nice...) and it suddenly seemed like I'd spent a fortune this month. I couldn't understand it - it's my first month for Vodafone and Sky but that shouldn't come to more than £70 between them. Mournfully, I decided that I definately couldn't have the computer :( Then suddenly, it clicked. I'd included an estimate for this months credit card bill. But I don't have to pay that til next month! No wonder it looked like I didn't have any money! So all in all, it's actually pretty good as although it would leave me with not much spare lucre I could pay all me debts for the next month including this credit card bill without getting paid. Of course then I'd be stuffed for rent but still, I think that's pretty good. So, the question is do I keep up the good work, or do I rest on my financial laurels and blow it all on this laptop?