Suitors of Porto striker Vincent Aboubakar have been told they must fork out 50 million euros to prise the Cameroonian away this January.
The forward, heavily linked with Swansea last summer, is enjoying a prolific season in Portugal.
He has scored 18 goals in all competitions so far this campaign, and has attracted admiring glances from other continental powerhouses.
Local outlet Record (via Sport Witness) state that his form is "fuelling the appetite for financially powerful clubs across Europe", and that a 50 million euro release clause was inserted into a recently signed contract.
That, Porto believe, will be enough to ward off "transfer harassment" until the summer.
The Telegraph reported this week that Swansea were set to revive their interest in the 62-cap international next month.
Speaking in July, he said: "I'm going to England, Swansea has a proposal. I do not want to miss it.
"I talked to my manager, I do not want to miss the offer Swansea offers."
If Swansea are serious in their interest, they will have to sink deep into their pockets.
Paul Clement has been told he will be backed in the January transfer window – if he can keep his struggling side in with a fighting chance of avoiding relegation.
Jason Levien was at the Liberty at the weekend to watch the 1-0 win over West Brom.
