Just curious... What are you CSing? Lately I've been thinking of gambling everything except for my weapon away (just in case any friends want to boss occasionally) for that exact same reason. Easy way to get rid of this maple addiction. End up down? Quit. Break even? Try again. Up? Maybe stay.
My question though is this. Why are you selling your items if you are quitting? Why not just give it away? Unless you have secret plans to come back at a later date, which is not actually quitting. Makes no sense to me.
The answer is literally in what you quoted lol; "quitting sell for gamble Cs" The items are his, he's free to do whatever he wants with them. I don't blame him for CSing, it's fun when you have nothing to lose like OP does in this case.