Any idea how much to unbuckle alloys?

Depends where the "buckle" is on the wheel. If it on the rim of the wheel, it works out at roughly 45 quid a wheel. If its towards the centre of the wheel, if it is too badly damaged the wheel is scrap, as per cdcs answer. If it just dented or slightly twisted, they can be repaired, but you could pay up to 50 quid per wheel in such cases. There are specilist alloy wheel restorers, best look on google for wheel specialists in your area.