Ahh, it's the way uni life is unfortunately...going out and getting lashed is the main social thing to do. It's sad, but there we go.
It's a shame that you're spending so much money on tickets/entry fees, drinks and things when you could just be spending £2 on a blockbuster DVD rental. Perhaps you could invite people over a few times a week (different groups of people of course?) or have a house/flat party? There's nothing wrong with having a couple of nights in by yourself either - I'm not going out tonight for Halloween because a) I'm so tired from the past 2 nights b) everywhere is going to be so rammed and expensive and c) I'm going out tomorrow for a Halloween party and have a long journey on Sunday, so I'm just having a cosy night in eating Marmite on toast and watching Grease.
Nothing wrong with that methinks, just don't become a social recluse. If you go out just a few times a week you'll appreciate it more. Going out every night gets boring after a while.