1) how many pairs of jeans do you have?
me - one pair at a time.
2) after how many wears on average do they get washed?
me - generally every other load, so about once a fortnight
3) what would you spend on a pair generally?
me - between £25 and £40. you can't really go around in £10 jeans, and obviously there's no point in spending lots of money on casual trousers, irrespective of what brand's on them or how much longer they might last.