The product, which is a watchable movie

Hi,

First, you would have to setup a page with a player for that movie.
For example, you could use extensions.joomla.org/extension/allvideos/ to have the player in a Joomla article.
Then, you could configure a menu item to access that article with an access level restriction so that only the users of a specific user group can see the menu item and access it.
Then, you can use HikaShop + HikaSerial subscription ( www.hikashop.com/component/hikashop/prod...ikasubscription.html ) to sell a product which will create a subscription for the user after the purchase of the product, and have the specific user group added to the user account while the subscription is active.
Once the subscription expires, the user group will be removed by HikaSerial from the user account and the user won't be able to access the video anymore.