Prosites memory limits

We are running a multi, membership site built on FrameMart with Marketpress and Prosites. We have the first level of membership set-up with 50 Mb of upload limit and the second level at 500 Mb.

When a new member adds a site to our “member template” and creates their own site and then attempts to upload any graphics – even a 80K header – we are receiving a warning that the upload limits have been reached. When I go to Prosite settings and increase this first level also to 500 mb – then we can upload content.

It almost seems to me that all the sites together are sharing this memory setting –

if that makes any sense…

Thank you for any ideas you may have on how to resolve this issue