Well 80 quid is better than 150. Lets be honest no warrenty in the world covers driving over it in the car.....
Its called a crash replacement warranty/policy. Many people offer them on many different bike products.
Giro don't count driving over helmets as 'crash damage'. Besides, giro's crash replacement really is only about 10% less than CRC prices (if that).
So Garmin's offer is pretty good, it was even just about worth it on my ancient 305, could have got it fixed and flogged it on ebay for a profit despite being 5+ years old!
or, you spend £150 on an edge 500.
and when the wheel-sensor packs up within 8 months, they could tell you to...
'buy a new one?'
£16 from decathlon, a pain, but not worth complaining about?