how are people so sure the negotiations went "fast". no one here knows how long we were in talks with Vidal, his agent and Bayern before this deal finalized or before the story came to the media. knowing that the guys running this clubs are not retarded but rather among the best in the world at what they do, it is more likely that we were negotiating with Vidal and his agent for a contract renewal (because his contract was until summer 2017 so he would been entering his last year of contract next summer) before it became obvious he wants to leave and when it was obvious, entered negotiations with Bayern. that could have been in February, March, April... none of us knows when. also, how are people so sure anyone would offer more than Bayern did. Real was interested (apparently, forgot source) when the Copa America was still on. what if they were offering 35M max and thats the reason we accepted Bayerns offer (if they even were interested. like i said, dont know the source).
here is another scenario - Vidal wanted to leave last summer (because Conte, EL, lack of fancy names coming in, money, random South American reasons..., there could be a lot of reasons) and we convinced him to stay an extra year because we wanted to make a final push in the CL while Pirlo and Tevez are still here. he didnt really look happy during last summer or at the beginning of the season.
another scenario - when Vidal arrived here 1st, he signed a 5 year contract until 2016, but when he was renewing (December 2013, after we gone out of CL) he prolonged for just one extra year, until 2017 and he got a great pay rise. was that a way to convince him to stay another year? possible.
my point is, this Vidal sale could be a story thats running back from 2013 even, we dont know the background talks and negotiations, and thats why its very childish to come up with stuff like "we should have got more", "he had a contract, we should have just kept him", "we rushed his sale" or "we should have offered him a higher salary". its much more complex than "hey guys, Vidal is for sale, whoever offers most gets him". even if it was this simple, it is still a question if anyone would offer even 50M, yet alone more than that like how most of us here rated Vidal.
tl;dr we know shit about how and what happened, stop bitching