Song is believed to be on a contract worth between £70,000-£75,000 per week at Barcelona.
But the price of persuading him to the east end is understood to be an £80,000 weekly package .
It was originally thought the Hammers were contributing 75% of his Barcelona wages as a fee but we have been told categorically this is not the case.
The huge wages puts him just behind Andy Carroll as the club’s second highest wage earner.
As previously revealed on Claret and Hugh, Sam Allardyce started confidential negotiations with Song in secret many weeks ago for fear of it leaking out.
After transfer failures with Modibo Maiga and Alou Diarra and some would argue Andy Carroll and Matt Jarvis, Allardyce has certainly put his neck on the line by investing so much wages in one player.
We understand the loan from Barlcelona is believed to last until May and will cost the Hammers just over £3m
The source told us “We are giving Song MORE wages than he was on at Barcelona, that’s why he came.”