Valencia rejected the west London club's advances last week because they were in advanced discussions over a £36million deal to take the striker to the Bernabeu.
However, with interest also being mooted from Barcelona, Manchester City and Manchester United, Villa's debt-hit club are holding out for a fee not much over the £40m that Chelsea were understood to be happy to bid.
Choices: In-demand Villa has a wealth of clubs interested in his services
The deal would be complicated by the 27-year-old's preference to stayin Spain, but he is running out of options with Valencia keen to selland Barcelona also well short of the asking price.
Barca's vice-president Rafael Yuste says his club are in talks to sign the Euro 2008 top scorer, but they are at least £10m short of the asking price.
'There are many players who are interested in coming to play at Barcelona and I think that people have to know this,' Yuste told Radio Catalunya. 'The talks (over Villa) are absolutely open.'
Both Madrid and their Nou Camp rivals warn they will not be ripped off and are ready to fight it out for Atletico Madrid striker Diego Forlan, who has a release clause set at closer to £30m.
Barcelona and Real are fighting it out for Forlan, pictured during Uruguay's shock 3-0 defeat to Venezuela
John Terry and Frank Lampard have both encouraged Chelsea to sign Villa and, with 87 league goals in 129 appearances for his current club, he is seen as one of Europe's hottest properties.
Valencia have debts of about £470m and hope to maximise the fee for Villa in a bid to hold on to David Silva, who is fancied by Liverpool, Real Madrid and Manchester United.
The club are ready to offload players who have two years left on their contracts.
They include defenders Raul Albiol, Carlos Marchena and Emiliano Moretti, winger Vicente Rodriguez and former Newcastle United midfielder Hugo Viana.
Giant Serbia striker Nikola Zigic could also be up for grabs, with Sunderland boss Steve Bruce understood to be an admirer. Villa to choose between Real Madrid and Barcelona as Catalans open talks with strikerCosta fortune club: Villa deal will take Madrid's spending to £170m in six daysValencia snub Chelsea's Villa approach as Atletico demand £55m for AgueroCHELSEA FC