£50 I'd say. I don't really spend that much in general (not because I can't, but I don't generally feel the need to). So if I want something, don't tend to care how much it is, I just get it. Plus I'm fairly well off, and my parents like it when I spend their money, they feel like they're working hard to earn it so I might as well use it.
And while my student loan isn't a lot, in fact my accommodation is more expensive than the loan given to me, I get more money from rent coming in from tenants (flats in my name that parents have bought). So I never really worry about how much money is my bank account, there's more coming in than out.
I think me and in general my family (though my parents don't necessarily want to me to be), have a general habit of just not spending much, there just isn't that urge. My parents don't own any flashy cars or anything even when they could afford it, they just don't want it, nor do they tend to splash out on expensive TVs, holidays, alcohol, material goods etc. Only thing they do is houses/property and that's only because that's an investment as house prices tend to go up (and they buy property, do it up with the intention of it being worth more than before).