An £83million (€100m) buyout clause represents value for money for Porto star striker Hulk, according to his agent.
Chelsea have been linked with the Brazilian for several years and the speculation has only increased since Andre Villas-Boas swapped Porto for Stamford Bridge.
Porto president Pinto da Costa dug his heels in over the weekend and insisted Hulk would not be sold for anything less than his asking price.
The fee would break the transfer record of £80m Real Madrid paid for Cristiano Ronaldo, but Hulk's agent thinks it is a reflection of his client's ability.
Representative Teodoro Fonseca told Radio Renascenca: "Hulk is one of the best players in the world and he is being followed by big clubs in Europe.
"One hundred million euros is not such a high figure. Every European club knows that the money spent on him would be compensated by his talent.
"A Chinese club is already paying £8.4m per annum to an athlete and some Russian clubs are already paying £16.8m."
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