Saw this in the big Cardiff store, for each season. There were all seasons available, but of course this might differ per store.
Next cheapest £9.99 at Play.com. Great bargain for 5-discs of great comedy.
"Philadelphia resident Will (Will Smith) is sent to live with his exceedingly wealthy Bel-Air cousins and finds that his street sensibilities cause havoc with the well-ordered lives of his distant family!