Barry and Milner both earned sizeable increases in their salary when making the move to Manchester City in £12 million and £24 million deals, respectively, in the pre-Houllier era.
Houllier said: "If sometimes, if you ask some players would they like to be one year younger, I think they would take it and consider things differently. Money doesn't buy you a regular place in the team and what players have to do is to think about it. You want to play. A real player has got the desire for winning and also a love for the game and wants to play."
Villa are bracing themselves for a battle to hold onto Ashley Young this summer with the England player being linked with the two Manchester clubs, Liverpool and Chelsea.
Houllier believes Villa will do everything possible to keep Young and reiterated talks over his future will be held in the summer.
He said: "I think the club will do what has to be done to keep him.
"At the moment he is a Villa player and his contract does not end to 2012.
"He said we would look at that at the end of the season and we respect that."
Source: PA
Source: PA