Hi to all forum members. In internet I find this intresting plugin for osclass (please feel free to use it in yours projects ) https://sourceforge.net/projects/osclass-oldpriceplugin/ , but I do not so well understand how to installate it?. Where exactly insert it's hooks that script will work well?! If there is somebody whith more experience can explane it i"ll be very grateful.
P.S. Moderators of Osclasspoint, I hope this is not against the rules of the forum, if so then delete this post, but it still seems to me that you could add this plugin to the list of your free plugins for the benefit of all and to your osclasspoint ecosystem, I hope for understanding.

@Newbie
I never saw this plugin, it should have some kind of docs/configuration page with details.

There is only file installation.php and this is what inside;
Installation:
Just add the code to your theme for Listings
<span style="float:none" class="price">
<s>
<?php osc_run_hook('item_oldprice'); ?>
</s>
</span>

Just add the code to your theme for Premium
<span style="float:none" class="price">
<s>
<?php osc_run_hook('item_oldprice2'); ?>
</s>
</span>

What can it be "for Listings" and "for Premium"? I even don"t see the plugin in plugin manager of osclass only in files

@Newbie
Name of plugin folder is wrong.

And what it's right name for the folder must be on your opinion?

@Newbie
Right name is inside of ZIP archive.

I have tested the plugin yesterday and it sucks.... Better is to spend a few cents and buy price-comparison-plugin https://osclasspoint.com/osclass-plugins/design-and-appearance/price-comparison-plugin-i178
Using old scripts who are free mostly gives you a cold shower later when your website is more successful...
Just in case u use the free plugin, the map under oc-content-plugins needs to be renamed to oldprice_attributes
If you want to display the old price you open item.php and add <?php osc_run_hook('item_oldprice'); ?> where price is....
For premium <?php osc_run_hook('item_oldprice2'); ?>

Thanks I"ll try. And I bought this plugin and at the end of translate it. But it's not the same thinks "old price" it's for marketing and Price Comparison plugin it's for statistics. But thanks anyway:).

@Newbie

I am using the price-comparison-plugin and i am not using it for statistics but only for showing old price and new price as in attachment .
The free one was not working correctly and updates wrong.....
Code for veronika on how i integrated it is on forum https://forums.osclasspoint.com/general-plugins-discussion/display-price-old-and-new/msg30530/#msg30530

Maybe you right, and I have Alpha them...