Developer content portal

We have built a multisite content portal with a subscription system in WordPress (Restrict Content Pro). It is a simple portal (magazine style) with articles and categories. You can find an example here: https://education.trendforce.me/. The design has a central administration (of content, users and usage statistics) and the option to install multiple front sides (multi sites).

Due to the problems we have with the (stability) of WordPress, we are looking for a different solution. For example, by combining prismic and nuxt.js. We are also open to other ideas.

We are looking for a long term relationship.

The features: login, account, favourites, tags, 'restrictpro-like' features (subscribing / access to content).

We would like to receive a time & pricing indication for frontend (for example nuxt.js) and backend (for examples prismic)