Rice will cost a bomb, possibly second only to Kane. However there's a reason behind the madness.The homegrown rule is something that we need to consider especially since 5 HG players will probably leave next season (Hendo, Heaton, Maguire, Jones and McT). But there is far more to it. First of all Rice is at the right age. At age 24 you can get 8-9 good years out of the guy.
Someone mentioned Maguire. Attitude wise Rice is anything but Maguire. At Leicester, Maguire was always surrounded with experienced/influential players like Morgan and Schmeichel. Once at United it took us very little to understand why. The guy is thin skinned and he needs to be guided. Rice on the other hand had become West Ham's captain at 23 years of age replacing a player that pretty much played in that same CM. Did that hit his performance? The answer is no. He's actually went from strength to strength and that despite playing in a team that is struggling.
Now let's have a look at his attributes. Defensive wise Declan is a beast. This year he was a duracell bunny on the pitch (second only to Ward prowse in terms of distance covered). He topped the list in terms of interceptions as well so he's both hardworking and can read the game very well.Technically he's also very good for a Defensive minded midfielder. His passing rate is that of a high end type of deep playing playmaker and is superior to the flavour of the month Caicedo.
Tactically I believe that Rice should be given priority just below the STK position. We only have one DM and he's 31. Casemiro is great but legs are the first to go and players like him will age badly. Think of an ageing Gattuso and Keane. They rather see red then being constantly disrespected by some snooty 20 year old something with pace. Rice will learn the trade from the best (ie Casemiro), he'll add mileage to the Brazilian's career and we'll finally have a CM that would be as hard as nails second only to the Ince-Keane duo.