Hello, i´ve a question of a thing that i don´t know yet if it is possible to do.The thing is,  i want to have a extra field named "price" that only appears when for certain users. Is that possible?I don´t want to sell thing directly on the web site but i want to show the price but only for some users.I wonder if i associate more than 1 extra field group to a category or something.it´s just an example.If not, can any one tell me other option to do this. Thanks

I have a solution that worked for me.

In "joomla extensions" -> "content restriction" - > HIDER

It don´t hides the extra field but hides the text inserted on an article.

It´s simple to use. For exemple: {admin} text {/admin}

It´s well exlplained how to use on the site.

hope this can help someone