Well said, but most of what you said is still arguable.
We have no idea how big is our transfer budget. Amauri and Xabi Alonso cost circa 30m euro (+Nocerino and half of Lanzafame).
Since Juve are selling Tiago, Marchionni and Almiron (and since Blasi is finally sold), it's expected the money spent for Alonso to be compensated with the money we'll get from the sales of the above mentioned players (probably some 1 or 2m left for Juve).
As you said, there are no superstar LB's, no Roberto Carlos on the market. The LB we'll buy will cost 4,5,6,7m euro.
To sumarize, the money we're paying for Amauri and the money we'll spend on LB, around 17-18m total, are the only money Juve will be paying.
Then there is Criscito, wanted by Genoa (they offer 3m eur, Juve want 5.5m) and even Molinaro. I'm sure some mid-table teams will be ready to pay some small sum for a player who was a regular in Juve, as bad as he was.
Selling these two and we're left with some 10-13m , lets call it cash money, that Juve will be paying.
If these 10-13m will stop us from buying a quality CB then buying Amauri is maybe a mistake.
But if such a, relatively small, sum will stop us from buying a quality CB then we don't even deserve to buy a CB.
So it's a question of our budget actually. If our budget was 40-50m eur (not counting player's sales) then there will be no problems. But we don't know if the 40-50 millions were newspaper speculations or a fact.
Personally, I doubt our directors would have bought Amauri if our budget was so limited.