Don't show product price in some categories.

How do I get in some categories on the product page does not display the price of goods?
But the rest leave as it is.

You could remove the price of these products no ?

No, I can not remove them. I need them for further calculations.

Then you would have to edit the file "listing_price" of the view "product" via the menu Display->Views and add a condition to return or not before the code of the page based on the current category.

How should look this condition? To weed out some of the categories.
Can you give me an example code please.

Well, you first need to load the categories of the current product with a mysql query. The product id is available in $this->row->product_id. Then, based on the results from your mysql query, you can decide what to do...

Thanks, I'll try.
By the way, I actually even easier to select products by id, that price will not be displayed.
(I have only few of them, but in different categories)
Later write the result.

I figured out how to not display the price of the product by ID.
But there was the following complexity...
The product have characteristics and it appears that each characteristic - a product with a different ID.
Besides, as I understand it, the characteristics do not have bindings to product category?

For now, I made ​​sure that did not display the price of all products that have the characteristics, but this is not a complete solution for me because may be other products with the characteristics, in which will need to display the price

How to remove a price only for those products which do I need? How best to do this?

For the products with characteristics, the product id should be in $this->element->main->product_id

Thanks, it helps.
I've blocked "price-listing" for my 3 products by main product ID.