Sorry I got these shoes mixed up with a similar style. The price is actually £285 / $560 on US site.
$560 is closer to £350, not ridiculous but IMO expensive for a rubber soled shoe. If you love them you need to get them!
cole haan makes a similar shoe thats VERY popular among younger people called the lunargrand. the price range retail is from $200 upwards to $280 for special editions at cole haan. im not familiar with cole haan either, but a check on styleforum reveals that the soles are glued with cole haan shoes. i imagine the leather must be better also with paul smith. has to be to for this shoe with a rubber sole, being 2 and half times more expensive than a similar rubber sole cole haan: