1. (2023八下·青田期中) 阅读下面短文，回答问题。

My feelings were the same as the fine weather on that day when I was passing by a yard sale. I decided to stop and see what the lady was selling. The woman was an old lady with health problems.

Of all her used things on the table, the toy plane was what I wanted most. My son was sure to love it. What's more, I wanted so much to buy something from her because she was poor and suffered from illness. I was expecting to spend a few dollars until she told me that she had to take the toy plane out of them. With a puzzled expression, I asked her why.

"That is my son's fifth birthday present." she said.

"Your son's fifth birthday present?" I said in surprise. "But how old is he now?"

"Oh, he should be 50 this year, but he died 10 years ago. He used to enjoy it as a child. "

That broke my heart! At that moment I knew I had to do all I could to help her. I asked her how much all of her things would be worth. She replied, "$75."

I passed her a banknote of $100, and had left with things before she gave me her $25. I could know she thanked me ever so much. I felt good to be able to help her out.

1. （1） How did the writer feel when he was passing by a yard sale? (not more than 9 words. )
3. （2） Why did the woman take the toy plane out of all things on the table? (not more than 8 words. )
5. （3） How much did the writer pay at last? (not more than 6 words. )