With rumours rife of a departure from Leeds, Paul says the huge price tag that has been placed on him in some quarters could end up being paid.
"I don't think any footballer is worth £30m - that is my opinion," he says.
"I think valuations have gone extortionate and completely outrageous; the person on the street must be saying 'my god, how can a footballer be worth that - it is not in the real world.'
"But the going rate nowadays is that for a player of his nature, so I am sure someone might pay it.
"Rio has been fantastic in the World Cup but everybody knew what a good player he was; sometimes when you get a run of games in the tournament some players really come to the fore, and I am sure he is grateful for the opportunity to play."
As, indeed, is Trevor Sinclair, about whom Paul says:
"It just shows you what a strange world football can be; poor old Trevor had that terrible Thursday before the last day of the season when he didn't know if he was in the squad.
"Unfortunately, he wasn't, and he was so down, but this goes to show how fortunes can change - and he is doing himself, his country, and West Ham proud."
Paul does not understand why he was criticised for returning home when he was put on standby and adds:
"His wife is pregnant, and people must understand that players have families.
"It all seemed quite amicable with Sven though, and it is all done now.
"You have only got to look at his performances to realise that he is becoming a better player; he has grown in stature in the games.
"He has grown in confidence since he has got out there."
Joe Cole has had somewhat less action, of course, with just the substitute appearance against Sweden, and Paul says:
"Joe is having to sit on the sidelines, but it is exactly like club football that you have talented players waiting for their chance.
"But he has to be patient, and while the players are there doing the job he has got to hang in there - and you never know what is round the corner.
"It is very frustrating for those sorts of players because they go out there full of optimism; the team wasn't quite finalised at the start and they have just missed out.
"I am sure they are enjoying the experience and they are part of a squad that has been doing well - that can only be for good for them, but I am sure they want to get stuck in and be playing."
Paul says that David James will be a strong competitor for David Seaman's shirt after the tournament, adding:
"David is in pole position; he is improving as a goalkeeper each year, and you can see that in his performances.
Speaking ahead of the Brazil game, Paul says of it:
"We are solid and strong whereas Brazil are the opposite with flair, flamboyant players - but hopefully a few weaknesses.
"The winners of the game can go out and win the trophy; that is how big the game is."