Custom Application Limitation?

Hello we are looking at upgrading our membership to a Developer package so we can get access to CB Subs and Package builder.

We are looking at being able to put some limitations on something, and were wondering what the correct method for this would be?
At preset we are thinking the way this would be done is with CD Subs, CB Conditional, CB Gallery, and CB Fields

2 Months Free membership = 5 free posts into a directory
6 months membership costs $X = 10 posts into a directory
12 months membership costs $Y = 40 posts into a directory

The directory has the following features;
Banner image 1000px x 200px
Lead image 600px x 450px
500 word description
Youtube or Vimeo video link

The part that will be interesting is can we randomly pull the banner, and display on a model on various pages as an advert?
and can we restrict the images uploaded to separate groups of items,
i.e.
each post has the banners, article 5 images, 1 video and the 500 word description.

Depends on if whatever you're using for a directory supports the functionality to limit the number of posts an individual user can make. CB Package Builder is not a directory and can not fulfill that role. CBSubs can not add features that do not exist. It simply can extend what already exists (e.g. say an extension has a way to limit entries per user.. CBSubs theoretically could extend that with a plan by increasing the limit). I suggest trying out CBSubs on our demo site to get a feel for what it can and can not do and how its integrations work.