Value is inconsequential, buying strength and willpower not to sell are the only factors in play:
Fofana - played for a team who finished in 8th bought by a team who thought they could beat the transfer system and have paid horrendous sums of money for 18 months - they're being found out and have to stop spending pronto.
Caciedo - owned by an extremely well run club who don't have to sell at prices they don't want to. Also not a CB. Also bought by same team that thought they could beat transfer system, also bidding war with RS.
What team is going to offer £120m for Branthwaite out the block? If a team offers £75m to 777 (or whoever) do you think they will play hardball like Brighton?
Lets not overlook - I think he is an exceptional player, but I think getting 150% of the world record CB fee is not realistic. I think getting £100% is a huge stretch given the circumstances.