Limit the number of records a client can create

[billhobbs]

I'm working on a site where individuals can list property for sale. Once a client has purchased X amount of listings I want them to have access to upload pictures text etc. for each item. My question is how do I allow them to create 3 listings if that is what they purchased? I can give them access to create records but I need to be able to give them access to create the number they purchase.

[Piranha]

Basically you do it in steps:

1. Get the number of purchased listings from the database.

2. Get the number of current purchases.

3. If the customer have purchased more listings than he currently have allow them to add another one.