Discs can be skimmed to restore the braking surface provided they are not too heavily worn. Some places can do this with the discs in situ on the car. Might prove cheaper than new discs and pads all round.

Before the next MOT perhaps it would be a good idea to take the car out and do some heavy braking from high speeds to clean up the discs a bit.

are you sure you dont mean the none braking section of discs ie outside edge and inner hub area of disc as theres been a lot of disc failures with mot by a national co

Front discs for a Aygo can be bought for 16ukp a pair.

My DB w211 has just had its first new front discs at 79k its on its third set of pads a colleague with a Volvo V70 is on its original discs at 85k and seem good for many more miles.I am sure its how they are used that determines the life span and not the mileage.

Depends on what you mean by last,ie rust or brake use,some failures are for rusty discs nothing to do with actual braking area of disc,also services as we all know are not done as they were 40 years ago,which is also becoming harder to recomend garages now