Tesco probably bulk buy these products to sell in their 'half price toys' sale, which they hold at least once every year as a Loss Leader (I suspect). They probably wouldn't stock the yellow school bus though, because UK children would be unfamiliar with the idea (except from watching Simpsons or other american TV programmes)- home to school transport in the UK, where it exists, makes use of 'standard' buses and coaches. Ambulance and recycling trucks are found on our streets however (right hand drive of course, but children may not really mind that).