At first the government tried to buy the collection for less than $25 million.
Spain then bought the collection for $350 million in 1993.
But the Spanish government couldn't afford to buy the collection.
Now, if everything goes as planned, Spain will pay a reported $500 million to buy the collection.
The strategy, she says, was to find someone who would buy the collection and donate it to the museum.
Suddenly he wanted to buy the entire collection of whatever the booth held, if she wished it.
His collection was bought for the royal museum of Berlin when he died in 1873.
"It is interesting to me that when store buyers come to buy the collection, they follow the same procedure," she said.
The collection was bought "for the nation" in 2008.
She tried to sell it to Banks, but he was no longer interested; instead an acquaintance of his agreed to buy the collection.