Upload limits are not granular enough

I've recently purchased a hosted package with IPS as I didn't want to invest in a licence until I know my venture is going to be a success.

The package has a very specific disk space limit which, once breached, would require a step up onto the next package. I wanted to prevent the space being used by those who are too lazy to optimise their images prior to upload (it being a photography forum) but I can only limit the uploads globally or on a post-by-post basis.

This doesn't give me the level of control that I need.

Global Upload Limit

I don't want to impose a global limit on uploads as I expect my users to post images as part of their use of the forum. The point is to post images so a global limit would be damaging to this.

Per Post Upload Limit

I don't want to limit the upload by post because some members may be posting only one image, some may be posting several. These images all need to be of a particular standard. A per post limit means to post more images one must lower the quality of them.

The control I would like to suggest and require to successfully implement on my forum is to specify an upload limit on a "per upload" basis. Each file should, individually, come to no more than an amount I set, but I am unconcerned by how many files are uploaded.

Example: You can upload up to 30.00MB of files (Max. single file size: 30.00MB)

What would be better: You can upload up to 30.00MB of files (Max. single file size: 512KB)

When disk space can come at a premium, it seems odd that uploads cannot be controlled at a granular enough level to effectively manage and predict usage.