HOLIDAYS!!
Weekened breaks with mates, start off as a cheap break - then you end up spending a fortune. For example - first day in Amsterdam I spent £280!!! On what? Alcohol mainly, but how is it possible to spend that much??
I bought a Diesel jacket for £200, I've worn it twice, I got it almost 2 yrs ago.
Random cables, and stuff like that.
EDIT: A Mercedes CLK 230 for £4,000. When i saw it I though, hmm this is not in as good condition as I expected. My girlfriend said, no no for it's age it's fine...BUY IT. I kept thinking, then against everything my head was saying i bought the blasted thing. 2 months later I spend £1,000 on making it look more pretty. For £4,500 I could've got a much better example. Then again i've used the thing about 10 times since i bought it in August...i don't even need it.