I'm going to a festival in a few weeks time and I'm looking for a cheap bag to keep a few bits and bats in (warm clothing, drink etc.). I really hate spending money unecessarily (no doubt I'll fit in here!) so I'm looking for something like this: http://i128.photobucket.com/albums/p172/jackt_bucket/qd71.jpg
but dirt cheap!
I've had a look in a few sports shops and they tend to be around the £5 mark, but don't have a zip pocket (which would be very useful). As far as I can see on their websites Tesco et al don't seem to stock anything like this. I've also had a look online and found that a lot of 'printing' companies sell them, but they all want to charge me at least £5 for delivery.
Does anyone have any ideas as to where I might get something like this (online or off) for peanuts?