'Denarii' in the Bible

But that bondman having gone out, found one of his fellow-bondmen who owed him a hundred denarii. And having seized him, he throttled him, saying, Pay me if thou owest anything.

And he answering said to them, Give ye them to eat. And they say to him, Shall we go and buy two hundred denarii worth of bread and give them to eat?

for this ointment could have been sold for more than three hundred denarii and given to the poor. And they spoke very angrily at her.

There were two debtors of a certain creditor: one owed five hundred denarii and the other fifty;

And on the morrow as he left, taking out two denarii he gave them to the innkeeper, and said to him, Take care of him, and whatsoever thou shalt expend more, I will render to thee on my coming back.

Philip answered him, Loaves for two hundred denarii are not sufficient for them, that each may have some little portion.

Why was this ointment not sold for three hundred denarii and given to the poor?