With their Champions League triumph overshadowed by the rebirth of Real Madrid's Galactico model, figures at the Catalan club have been quick to condemn Perez's lavish approach.
Defender Gerard Pique, in South Africa, suggested he was more "afraid of lions" than of Madrid, and economist Xavier Sala i Martin questioned where the money was coming from.
On Saturday, Barca President Joan Laporta quipped that "Real buy superstars, we make them." The two may be linked, however, as Perez's money may be coming from the same source as Barcelona use to fund their La Masia academy.
It is the Catalan bank La Caixa who put up the 57 million euro guarantee for Perez's presidential campaign and it is believed to be La Caixa with whom Perez has a line of credit.
Some sources in Spain suggest that credit has extended to the £213 million loan taken out to fund a spending spree which, as well as the £131 million invested in Kaka and Cristiano Ronaldo, is likely to encompass the Valencia trio of David Villa, David Silva and Raul Albiol in the coming weeks, as well as Liverpool's Xabi Alonso. Neither the bank nor sources close to Perez would confirm the reports.
In a country harder hit by the economic downturn than most, questions have of course been asked about the decency, let alone the wisdom, of such a large loan. Even Michel Platini, the Uefa president, has described Perez's plans as "excessive."
La Caixa are known as a major patron of Catalan arts and culture, while the bank also pays a premium for the right to be known as Barcelona's official corporate partner. If it is their loan bankrolling Perez, not only would their popularity in Catalunya be hard hit, but questions would be raised about Europe's two biggest clubs and fiercest rivals being funded by the same institution.