Buyer backed out after agreeing to a price

[mykia1794]

I had an item listed and a woman sent me a message asking for a lower shipping cost.  I told her I couldn't do that as the item was heavy.  A couple weeks later she contacted me again and offered me a lower price.  I messaged her back giving her a counteroffer a little higher.  She asked if she could pay in two weeks.  I told her that I would be willing to pull the ad for the two weeks and when she was ready, she could message me and I would list is as a Buy It Now at the agreed upon amount. (There were quite a few back and forth messages but I am making this short)  I was very clear about the price I would take and I even got her zip code and figured out exactly how much shipping would be for her.  She agreed to all of it and said she would contact me when her money came in in the two weeks.   As agreed, two weeks later, she contacted me saying she was ready.  I sent a message with the agreed upon amounts to confirm with her but didn't get a response.  The next morning I heard from her saying she was ready to buy.  I listed the item at the agreed upon price and shipping and waited for her to buy.   A little later, she sent me a message saying that she thought she remembered that we agreed on a flat price of $50 (it actually came out to be $56 and change) and she was going to check the messages to confirm that she was right.  I went ahead and copied and pasted the messages where I had clearly stated what I was willing to sell for in a message to her.   I never heard back from her again.  She didn't respond, she didn't politely back out, she just disappeared.    I feel that I bent over backwards to help her to be able to buy the item that she really wanted even to the point of not listing it for 2 weeks so she could save her money up.  I have proof that she agreed to the transaction, then she stiffed me with no word.   Is this legal?  Is there a way to give her a bad report as a **bleep**py buyer?  Or am I just an idiot for trying to be a kind and helpful seller?   I have all the copies of our communcations to prove that she agreed.  Will this help?  Is there a place to report this and if so, where do I do it?   I am relatively new at selling on Ebay so don't know everything I need to know, obviously.