Pogba - Worth £100m+ now easily.
Bailly - Probably worth more than £30m looking at the market, he's shown he's a really talented front-foot defender, just needs to stay fit, cut out the rashness and the lapses in concentration. Not a lot more, I just think given his age and talent he's more like a £40m player.
Martial - £38m I think initially, rising to £52m? United won't have paid all that yet, even so I think he's worth more than that when you factor in age, talent, potential and his current form. He's probably a £65m+ player nowadays.
Rojo - I'm not a massive fan of him as he can be rash and isn't very good technically but probably worth more than £16m, he's a great stopper-style CB. Gotta be worth £20m+, injury-record might hurt him a bit though.
Blind - Probably worth more than £14m now if United were to sell him. Not had a bad United career, still got years left in him, versatile and intelligent and good technically. £20m+
De Gea - Self explanatory.
Smalling - Worth way more than £10m. Probably around £25m-30m range.
Romero - Bit of a cheat one, but he was free, so...