Is it possible to make only detect duplicate listings, and do not mark them as spam or delete them?

Thank you

@Sergej Zaharenko
You can mark them as spam and then decide if it is spam or not.

As I understand, the plugin marks old ads as duplicate (spam) and new permits. Is it difficult to remake it, that new listings plugin marks as spam, and old ones leave?

Sorry for my English=))

@Sergej Zaharenko
Yes it would be very complicated, but more logic is to mark old as spam.
Reason is that you will get content refreshed, will last longer on your site.

The reason why I would like to do the reverse - monetization, old listings people can move to the top and buy premium. If the new copy Listing will be added, that there is no monetization, such as they always can add a new one copy, and it will be in the top.

I think you understand me =)

@Sergej
Got you.
You can try this.
Go to file:
oc-content/plugins/spam_solution/index.php

Find:
$item_check['pk_i_id']
Replace with:
$item['pk_i_id']