"Bale's a very good player," the Argentine told a news conference when asked about Real's pursuit of the Welsh winger.
"The numbers are lack of respect to the world in general."
Barca, Real's arch-rivals, splashed 57m euros (£49m) on their major signing of the close season to date, Brazil forward Neymar.
Nine-times European Cup winners Real appear to be close to securing the signature of Bale with local media reporting that after weeks of negotiations an agreement has been reached with Spurs, pending a final confirmation.
The player is expected to be presented next week - probably after Real's next league match away to Granada on Monday evening.
Champions Barca travel to play Malaga on Sunday, but will do so without World Player of the Year Lionel Messi, who is recovering from a bruised left thigh.
The Argentine struggled with injury at the end of last season and concerns have been raised that his latest setback, when he was substituted at halftime in the Spanish Super Cup first leg on Wednesday, was a recurrence of a hamstring problem.
"Honestly, I am not worried (about Messi) because I think he is fine," said Martino, who indicated it was purely precautionary.
"He has been fine since day one and he has been working during his holiday. He got here fit and he has been training every day.
"What happened the other day was coincidence. I think it is totally unnecessary to take risks at the start of the season."
Barca drew 1-1 away to Copa del Rey winners Atletico Madrid in the Super Cup first leg, and host the return leg on Wednesday bidding for the first piece of silverware of the new season.
In Messi's absence, Martino was asked if Neymar would be given his first competitive start for the club, after having gained a confidence boost heading the equaliser off the bench against Atletico.
"I don't share this idea that says that Neymar must take over and take the lead if Messi is not there to do it," said Martino, who has called for patience to let the 21-year-old find his feet in La Liga.
"We have Xavi, we have Andres Iniesta, Cesc Fabregas, Alexis Sanchez, Pedro. There are too many players to expect Neymar to automatically be in the starting line up.
"Nothing is going to shorten the time we think is necessary for Neymar to be ready."
Joining Messi in the treatment room will be Barca's Netherlands international Ibrahim Afellay who had surgery on a thigh muscle problem on Thursday, and who will be out of action for around four months.