What conclusion can be formed regarding Mr. Bennet's reaction to the news of the marriage of Lydia and Wickham?

Mr. Bennett's reaction regarding the possibility of a marriage between Wickham and Lydia shows that he is more relieved and happy to pay money for Lydia, for he believes that it will be better to stay married to a man like Wickham than have a ruined reputation.

Explanation:

When at first Mr. Bennett and the whole family came to know of Lydia's elopement with Wickham, they were devastated and alarmed at the same time. They had believed him to be of a bad character and a loose one too.

And then in Chapter 49 of the text "Pride and Prejudice", we see that Mr. Bennett is somehow happy to hear of the possibility of a marriage between the two. For he believes that a marriage of any kind is far more better than a bad reputation. He is also ready to pay money for Lydia's keep and even stated that "I should be sorry to think so ill of him, in the very beginning of our relationship". He seemed to accept or rather be relieved that they have a possibility of marriage and not stay as "loose" couple, bringing a bad name to the Bennett family.