Use "Upgrades" plugin to limit "Products" with MarketPress?

Hey...we're sorting through some various snags with a current project and have found solutions for most everything using off-the-shelf plugins here at WPMU. We're impressed. :slight_smile: This multi-site project is going to be selling the ability to create a "store" using MarketPress. It looks like we'll be customizing PayToBlog to sell the ability to create the store initially and would like to then limit new store owners to just X products (likely 10). Then, what we'd like to do is add the ability to add more products to one's store using "Upgrades" credits. So...I guess this post is asking two questions:

1. Can "Upgrades" be modified alongside MarketPress to allow for the purchase of "Product" slots?

2. Can a MultiSite "site" be set up/modified where a newly created site (again using Pay To Blog) only has the ability to have X products published.

Thanks in advance.