I would say, it's ok in my opinion given his age and how well he plays in his role. Also don't forget the competition between the clubs for Declan Rice. Some backed off from proceeding given his price but there were big clubs after him which were: United(last season transfer windows) and this transfer window- Bayern, City and Arsenal. Let's see how it goes, but I think he will do fine.
If you look at some of the rumors, there are indeed several big teams eyeing Declan Rice, but I see that Arsenal and Man City don't seem to be asking too much to pay Declan Rice because there are other players they are after. but for such Bayern Munich there is little possibility.
but I was just wondering at his age and at such a high price whether any team would really want to buy him. well, I know Declan Rice has a very good performance because as I said before that a lot of experience but his current age doesn't have a guarantee to come out with a stronger performance.