Cheap track chainrings
 

Does anyone know a place in the UK where I can find a cheap 1/8", 130bcd chainring? Nothing special, just something to get ridden into the ground on a work bike, thanks in advance.

Enough london couriers use these shops that I'm sure they'll have some in stock.

condor cycles - quite possibly the best bike shop in london
http://www.condorcycles.com/

bikefix and brixton cycles have good reputations too