Everyone has a price, and it just so happens that the club fell that Downings is £19m. The club is a business lets not forget.
People say we shouldnt be selling our best players, well if your best players dont want to be hear then its a little difficult.
The clubs stance was always that Stewart was not for sale, however since that statement i would expect that Stewart has made it clear to the club that he would like to move to Liverpool, the club then (and rightly so) assume Stewart no longer wants to be at the club and they have set his valuation which id £19m, which Liverpool will either meet and he leaves or they dont and he stays.
AVFC are not just selling there best players to line Randy's pockets, they are taking into consideration what the players wants, in this case it is clear that Stewart wants to play for Liverpool and has told the club this, that is why their stance has changed and they have set a price.