The 27-year old is currently on loan with the Potters and his form has been such that Pulis is keen to bring in permanently but not at that price.
"He won't be coming to Stoke for £6m. It's just ridiculous. It's too much money," said Pulis. "If they are sensible, we can do a deal. But they got him on a free transfer, so the price is not right.
"It has to be a sensible agreement. If they are asking that kind of price, then it's just ridiculous."
Pulis added he was desperate to retain Pennant but admitted that if Zaragoza cannot do a proper deal then the former Arsenal starlet would have to return as the Spanish club own his contract.
"There's stuff going on behind the scenes, but obviously it's difficult because you're dealing with a club abroad," added Pulis. "Jermaine's enjoyed it here but he's under contract with Zaragoza and if they don't want him to come or we can't do a deal, he'll go back.
"We're desperate to try to keep him if we can."