Is Being Nice Too Hard?: Helping Friends + Questions

I have a friend who I'll refer to as R and another friend I'll refer to as S.

So R is a citizen of Uganda who comes from wealthy family. Her dad works for the government and makes a lot of money and she's going to move back to Uganda very soon because she just graduated from college. Because she doesn't want to drive and the car she has a piece of crap, and her father has a lot of money to buy her a car if desired. Initially she wanted $1000 for the car but she couldn't find a buyer for it because most people didn't want to pay $1000 plus she's not that good of a salesperson so she changed the price to $600 so she could get a buyer. She then discussed with me and C that she was planning on giving the car away to a towing company or something like that for free instead of giving it to my friend C who needs a car. C made an offer to R to buy the car for $400. I should add that C is very good friends with R, and is one of her best friends in the state where we go to college. R wanted to sell the car for $500 instead of $400 that C could afford at the time. The same day that R and C and I were discussing her possibly giving the car away to C for $400, she told us about some guy that she cheated on with her boyfriend that she gave a necklace to that she thought was $90 when she bought it, only to find out that it was $300. She tried calling back the person who she gave the necklace to as a gift, however he wasn't picking up any of her calls. Plus she gave it to someone who's not even that good of a friend to her, who she cheated on her boyfriend with (and this is not her first time cheating on her boyfriend this is her second time from what I know so could be more for all I know).

My personal opinion is that she's being selfish and inconsiderate especially since she's willing to put more money towards some dude that she barely even knows instead of a friend of hers who's a true friend to her to help her out because she knows she's struggling with money, and she knows that she needs a car.

Personally it's really aggravating and unsettling to know that some people can be so selfish and have their priorities mixed up when it comes to being helpful to a friend. I Understand that different people have different thoughts and ideas on how they feel they should help other people, but I personally feel like it's wrong to think that way with any situation for any person. I know that I'm very selfless person and I like to help people a lot but I know that not everybody is as helpful as I am. Still I still feel like some people could be a little bit helpful especially when it's needed. The guy didn't even need the necklace that she gave him yet she gave him a necklace. She even said that the sex was bad.

I'm just disgusted and disappointed really.

QUESTIONS
1. Have you don't that to a friend?
2. Would you cheat on your boyfriend twice if you love him?
3. Are you broke and in need of help?