Can I have separate packages using upgrades?

If I use the Upgrades plugin, can I have different packages?

For example:

Bronze (cost 1 credit)
10mb webspace
4 themes
10 plugins

Silver (cost 2 credits)
10mb webspace
8 themes
15 plugins

Gold (cost 3 credits)
10mb webspace
20 themes
30 plugins

The silver package would include everything in the bronze package, plus extras, the gold package would include everything in the silver package plus extras. So, for example, a single plugin could be available in all the packages, the user would just pay for the package they want.

Alternatively, is it possible to give a credit price to individual items (plugins/themes/webspace), but also have a price on a collection of items?

Does this make sense?