It seems that Everton want Koulibaly as Stones replacement:
http://www.hitc.com/en-gb/2016/02/2...up-kalidou-koulibaly-as-john-stones-replacem/
http://metro.co.uk/2016/02/29/rumour-everton-want-transfer-of-napoli-star-kalidou-koulibaly-5724496/
http://talksport.com/football/evert...armarked-john-stones-replacement-160229186657
http://www.ilsussidiario.net/News/C...bbraio-2016-aggiornamenti-in-diretta-/683647/
I like Stones but as @BigDunc9 alluded to if you were getting 50m it seems a no brainer to replace him with a cheaper but good alternative like Koulibaly and we can improve the overall squad. The takeover kind of means that this probably wouldn't be needed though.