What limits?
We've sold over £105m worth of player in De Bruyne (£18m), Mata (£37m), Luiz (£50m) and spent that £92m of the £105m on Fabragas (£28m) and Costa (£32m), Matic (£20m), Zouma (£12m) we are infact making profit along with the fact £500,000 a week has been re-couped from Lampard (£150,000), Cole (£130,000), Essien (120,000) and Terry's reduced wages (from 175,000 to 100,000) means more money can be spent on players this summer. Having read the financial reports with FFP to consider, we could spend over £100m more this summer and still be complying with FFP.
Bertand £8m, Cech (£15m) Mikel £10m, Moses £5m, Marin £5m and other young players like Atsu (£5m), we can sell makes over another £60m in the transfer kitty. Pogba funds are available if Chelsea want, question is do they want to spend it all on one player.