Problem Creating new listing as a member

I was testing my website and came across the following….
I registered as a member and bought a listing package. That was fine. There is a maximum nr of listings that you can place per package. So I added a few listings and then I got the message that I reached the maximum listings, please remove a listing or upgrage the membershippackage before making a new listing. This is all good.
Now I want to buy a membershippackage (as a member). This is not possible. (see attachment membership package). In admin the field GENERAL SETTINGS>MY ACCOUNT OPTIONS>DISPLAY MEMBERSHIP PACKAGE is disabled. There is now no way that you can buy a new membershippackage or a per listing package. In my menu I have the page Create a listing, but you cannot go there because of the message that you first need te remove a listing or buy a membershippackage…
So now I enabled GENERAL SETTINGS>MY ACCOUNT OPTIONS>DISPLAY MEMBERSHIP PACKAGE (see attachment Membership package part 2). You can now buy a membershippackage, but not a Per Listing Package. I would like to have the opportunity to buy a Per Listing Package when I reached the maximum nr of listings.