Which universities should I be applying to?

Hi,

I'm new Just looking for some input from anyone that knows more about all this really...

I was a lazy git in school and although i've always been fairly bright i got the following A levels: IT (B), Physics (D) and Maths (U at A2 - C at AS).

Anyway, I've worked since, gaining some work related IT qualifications along the way. But after growing up a bit and actually thinking about what i want out of life, i decided i want to get myself a degree to open up opportunities that just arn't there for non-graduates.

I want to study either Maths or Economics, at the best Uni i can get into ideally, but I appreciate that these are competitive courses and i may need to be a bit open minded.

I am now in the middle of resitting my Maths A2 which ive been studying since Feb in my spare time/between temp jobs. Presuming i get an A, it would give me 280 UCAS points. What sort of 'tier' of university do you think i should be applying for?

Does my age (will be 23 when applying) and work experience/qualifications mean that i can 'punch above my weight' in terms of UCAS points? or will they not look at it like that as i didn't do well first time around and i'm not really that old for a mature student?

Obviously the UCAS application will have sway over this as well as perhaps interviews, but i'm just looking for a general idea from people?

Thanks.