It depends how you define input. It's not just about how much money is invested in a club by its owner. "Input" also takes the shape of management expertise.
And that, in many respects, is far more important than financial contributions. Take Portsmouth, for instance. Sacha Gaydamack put a significant amount of his own money into the club. Yet he made a complete dog's dinner of properly managing the club. Look at it now.
As to what ENIC have paid thus far, I can't say for certain since they have grown their shareholding over the years, in different ways and from multiple sellers.
At the time that they bought 27% of the club off Sugar, they already owned about 3%. They paid Sugar 80p per share, which translated into a little under ?ú22 million. Let's say that they paid a similar amount (although it was probably less) for their initial 3%. So they had paid a total of about ?ú24 million for the 30% of shares that they owned back in 2001.
They subsequently increased their shareholding to about 56% after the 2004 rights issue. That cost them in the region of ?ú11 million.
They then bought Sugar's remaining 12% for ?ú25 million in 2007, taking their shareholding to about 67%.
They contributed the entire ?ú15 million to the 2009 share placement, by which time, they owned some 86% of the company.
Various other purchases from shareholders large and small ensued. I have no idea what price was paid. At a guess, in the region of ?ú25-30 million.
So the total is likely to be a little over ?ú100 million. But who knows? Could be as much as ?ú120 million.