i would like to know if it is possible to create a website like this one extensions.joomla.org

You'll need to provide the name of the extension. Sorry, we do not permit new forum users to provide external links. I know it's a bit annoying, but it drastically reduces spam for us.

Also is it possible to allow the user to add article limited to a certain category of blog ? Depending on the access he has ?

Yes, CB Blogs can limit what Joomla categories blogs can be created in. You could also just use Joomla's submit article page and use Joomla ACL to limit what categories they can submit articles to.

With CB Subs, can i create different subcribitions depending on different field in the space they have ?

I'm not sure what you mean by. In the space they have? There's certainly a lot of interaction between CBSubs and fields that's possible, but you'll need to be more specific. For example you can have subscriptions available based off the value of a field or you could modify the price of a subscription based off the value of at field. You could have subscriptions also modify the value of a field on activate or expiration. There's a lot that can be done here.

Can they pay on stripe/Paypal ?

Yes, we support Stripe and PayPal.

If they don't renew the subscription, is it possible to unpublish what they created (the articles and there space) ?

Yes, it's possible to unpublish all Joomla articles they've created if their subscription expires using CBSubs SQL Actions to run a database query to do that.

Is it possible to do all this with CB + CBSubs or should i add more plugin, modules... ?

Possibly, but you'll need to clarify above what extension you were referring to. For example if you need profile activity feeds you'll need CB Activity or if you need profile media galleries you'll need CB Gallery.

You've a couple of options. You can just use profiles as those pages and add whatever features you need to those profiles. An example of a profile can be found on our demo site below.

demo.cbdemosites.com/profiles/susan

Another option is to use CB GroupJive. CB GroupJive is a lot more limited though. It has no custom field support and is more or less "feature complete". It won't have custom field support until a later rewrite, but it is possible to add new fields using CB Auto Actions however you need to be proficient in PHP to do so. Below is what a CB GroupJive Group looks like.

demo.cbdemosites.com/demos/cb-groupjive/all-categories/1-community-builder-add-ons/26-cb-template-changer

Below is the groups page that looks similar to what you've provided.

demo.cbdemosites.com/community/groups/

Personally if you don't need these pages and profiles to be separated I would go for turning your desired pages into just using profiles as they're a lot easier to customize.

Also what buddle will i have to take and how much would it cost ?

Depends on what features you need. Take a look at our addons below and see if you'll need them. You'll need CB Paid Subscriptions at the very least to handle the subscriber aspect of it.

www.joomlapolis.com/addons

We have a fully accessible demo below as well. Feel free to explore and make changes as it resets automatically regularly.

demo.cbdemosites.com/

We also provide a 30 day satisfaction refund policy, which you can find below, if you're not happy with your purchase.

www.joomlapolis.com/warranty