I can't recall exactly where I learned this activity from but I believe it's an interesting way of giving feedback to mistakes.
This semester I've started a project with students where each week they select a picture , write a text about it and send them both to a designated e-mail address. The texts written by students are not edited beforehand , therefore, throughout the semester I tried to address their attention to the most common mistakes using different activities. For more information about the project, read a previous post.
To play AUCTION is fairly simple. First you select sentences with no mistakes and sentences which contain the most common mistakes you want to draw attention to. You can have the list of sentences on a ppt, a word file or even a poster. Explain to students you will auction sentences and their goal is to buy as many correct sentences as they can. If they buy a correct sentence they will get their money back but if they get a wrong sentence, they will lose their money. If they don't buy any sentence, by the end of the auction, they will also lose their money. I used money from an old Monopoly game to give all my students the same amount of notes.
Then, the auction starts. As soon as a sentence is sold, the teacher writes the name of the buyer and the amount paid next to the sentence. After all sentences have been sold, the teacher collects all the money from students and starts correcting the sentences with the students' help. If a sentence is right its buyer has the right to receive the money back. Keep on going until all the sentences have been analyzed. The student with the highest amount of money WINS THE GAME. These are some pictures taken in class yesterday.