Sam Morsy is the latest player to depart the Proact, with Chesterfield reaping a financial reward.
In the past year Spireites have benefitted from the sale of five other high profile players.
The most recent was Armand Gnanduillet, sold to Leyton Orient in the past week.
That fee, around £35,000, wasn’t in the same category as the likes of Eoin Doyle, Sam Clucas and Tendayi Darikwa however.
Doyle was sold to Cardiff City on 2nd February 2015, for a fee believed to be between £850,000 to £1m.
The Irishman wasn’t far off a goal every other game ratio for Spireites, hitting the net 32 times during his season-and-a-half spell at the Proact.
Winger Roberts, League Two Player of the Year in 2015, followed Paul Cook when the manager left Chesterfield for Portsmouth.
That fee was undisclosed but £100,000 has been reported.
Chesterfield signed Clucas for an undisclosed fee, around the £100,000 mark, on 1st September 2014, and departed the club on 27th July 2015, earning Spireites approximately £1.3million.
Clucas scored nine goals during 38 appearances for the League One side and played a key role in their march to the play-offs.
Darikwa picked up four post-season awards at Chesterfield on 6th May 2015, and on 30th July he was a Burnley player.
The Lancashire club spent £600,000 or so on the right-sided player.
Out of the list of recently sold players, he stands out as a homegrown talent, having started his career with Spireites.