James has been linked with the pair's former club, Everton, as well as Crystal Palace.
The Independent reported earlier that Crystal Palace's approach for James, in whom Everton have also been credited with an interest, has been turned down.
That prompted another ex-Evertonian, Don Hutchison, to post on Twitter: "Crikey and people are moaning about (the) Harry Maguire fee."
But Reid, who coached James at Wigan Athletic last season and once managed Hutchison at Sunderland, replied: "Worth it I can assure you."
Worth it I can assure you.— Peter Reid (@reid6peter) August 2, 2019
That forced Hutchison to concede: "(The) gaffer knows".
Crystal Palace are said to want James as a replacement for Aaron Wan-Bissaka, who moved to Manchester United for a fee that was reportedly double that of their James bid.
And Everton have their own need to strengthen in the Chelsea youngster's primary position, after allowing Jonjo Kenny to join Schalke 04 on loan.
That has left just Mason Holgate and Cuco Martina - both of whom ended last season on loan at other clubs - as back-ups to Seamus Coleman.
What's the maximum amount Crystal Palace should offer for James?
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