Subscription levels is this even possible with Hika shop?

Hi,

Yes, we have developed a special extension, HikaSubscription to be able to do that with HikaShop:
www.hikashop.com/component/hikashop/product/cid-227.html

Hi,

The subscription capabilities are not in either HikaShop Starter or HikaShop Essential or HikaShop Business. If you need them, you need to also purchase HikaSubscriptions which will automatically integrate with the edition of HikaShop you're using.

While we didn't configure a specific page where you could directly test its functionnality on our demo website, the extension is installed there. So you could create a plan in the backend of the demo website, attach it to one of the products already there, and then, when you would purchase that product the subscription would be added to your user account.
So you can demo it on demo.hikashop.com yes.

And yes, you can use it to sell access to menu items for a set period of time.
You'll have to configure your plans to be linked to user groups of Joomla and restrict these menu items to the corresponding user groups.
HikaSubscriptions will then add and remove the user groups automatically upon purchase or expiration of the subscription.