Modules

Hi,
you can download those add-ons (and much more) from GitHub:
https://github.com/simpliko/wpadverts-snippets
At the end of the list, you have search-by-category and search-by-price.

You can save the whole directory in wp-content / plugins and use as a new plugin. Another option is to remove plugin header from the file and copy the code to functions.php.