Any club hoping to lure a big name away from Newcastle during the remaining days of the summer transfer window would have to make an astronomical offer to succeed.
Press Association Sport understands only bids they simply could not ignore would prompt the Magpies even to consider parting with the likes of skipper Fabricio Coloccini or midfielders Cheick Tiote and Yohan Cabaye.
Coloccini has been linked with Barclays Premier League champions Manchester City in recent days, while both Tiote and Cabaye have been touted as targets for Arsenal ahead of Friday's deadline.
Gunners boss Arsene Wenger has played down his reported interest in the Ivory Coast international, although Newcastle counterpart Alan Pardew will be a relieved man if he gets to Saturday morning without losing one of his key players.
However, potential purchasers will be left in little doubt that, with the Magpies not looking to sell, they would have to find in excess of £20million to give themselves any chance of landing a member of Pardew's blue chip brigade.
Indeed, it is understood that if Wenger was to pursue an interest in Cabaye, for example, it would take much of the proceeds of Robin van Persie's £24million switch to Manchester United to unlock the door at St James' Park.
The values of all three men have grown appreciably during their time on Tyneside with Coloccini recovering from a difficult start in English football to not only justify his £10.3million price-tag, but prove an astute acquisition.
Both Tiote and Cabaye, of course, are products of the club's much-envied recruitment policy which has seen chief scout Graham Carr identify players with potential and the Magpies snap them up at competitive prices.
The Ivorian cost Newcastle just £3.5million when he joined from Dutch side FC Twente during the summer of 2010, while the Frenchman's signature was secured from Lille in return for £4.8million a year later.
Both have been big hits in the Premier League with Tiote's all-action, aggressive style complementing Cabaye's cultured passing game, and both have played central roles in the club's return to prominence.
Pardew, who spent the first two months of the summer hoping no club would activate the £7.5million release clause in striker Demba Ba's contract, knows all players have their price following Andy Carroll's £35million departure for Liverpool just weeks into his reign.
However, he is desperate to strengthen, rather than weaken, his current crop and to that end, still has hopes of adding further recruits of his own.
Pardew has so far drafted in midfielders Vurnon Anita, Gael Bigirimana and Romain Amalfitano, and is keen to boost his options in both defence and attack.
His interest in Lille full-back Mathieu Debuchy and Twente central defender Douglas has been well-documented, while Carroll's proposed return from Anfield, either on loan or at a knock-down price, remains a focus despite the Reds' disdain.
But with all three deals having proved difficult to execute, the club has alternatives, although all activity will be governed by the insistence of owner Mike Ashley and managing director Derek Llambias that they will only do business on their own terms.