Everton will have to pay in the region of £50m if they are to prise Swansea midfielder Gylfi Sigurdsson away from the Liberty Stadium.
Swansea are yet to receive any official approaches from Everton and are frustrated by reports that the Merseyside club are about to launch a second bid of £35m.
After landing Wayne Rooney, their sixth signing of the summer so far, Everton are looking at a further three acquisitions, with the Iceland international understood to be top of that list.
Swansea are desperate to keep their player of the year and are frustrated by reports they feel are being used to unsettle him.
Sky Sports News HQ understands Leicester have made enquiries about the player's availability.
Swansea will not let Sigurdsson go on the cheap with one source close to the Swansea board telling Sky Sports News HQ: "Swansea will not be pushed around and are not looking to sell.
"They have a figure in mind that they feel represents Sigurdsson's worth in the market and if nobody reaches that they are very comfortable about keeping him."
Sigurdsson scored nine goals and provided 13 assists last season as Swansea retained their Premier League status.
In comparison to Sigurdsson, Everton midfielder Ross Barkley registered just three goals with six assists, while
Kevin Mirallas scored just three goals with two assists.
Sigurdsson was third overall in the Premier League in terms of goals and assists, behind only Kevin De Bruyne and Christian Eriksen.
He was also the only player from a team in the bottom half of the Premier League who had more than 20 goals and assists.
In May, Swansea's co-owner Steve Kaplan said: "We all know how important Gylfi is, just as he knows how much he's valued and loved here.
"There's been interest in him before - there were some pretty big enquiries about him last summer and in the January window - but we didn't want to sell him then and we don't want to sell him now.
"And neither do we need to sell him. He has three years on his contract and he's part of our plans going forward under Paul Clement.
"Our aims are to make sure that we build on the successful end to the season and that doesn't include selling our best players."