Is there a cheap way to repair a tyre?

I caught a financial cold recently when I picked up a puncture in a nearly-new Z-rated tyre and I had to get it replaced. Is there any guaranteed way I can avoid a costly bill if I get another puncture? 
Gary Harper, email 
 
Avon tyres have a scheme called the Road Hazard Warranty. If one of their radial tyres becomes damaged or punctured they will replace it free of charge, as long as there’s no more than 1mm of wear on the centre of the tread. To make a claim, you’d call Avon Customer Services on 01225-357750. They will then direct you to a participating dealer who has a replacement in stock and can check your wrecked rubber meets the requirements. All you have to pay for is the fitting costs.