As you can see from the threads, I've been messing around with the Upgrades plugin for the past day or so, but as I'm doing so, I'm realizing that it's really not for me.
I want to package a bunch of plugins together -- custom and open -- and sell my complete solution to folks.
The plan is to have no "free" version of my installation (don't worry, I plan on making some of our custom plugins open source).
So, what I'm really wanting is to charge folks as they sign up for a site. I'm fine using PayPal's recurring payments for this... but I'd really like to use an existing plugin before building a dreaded billing feature.
Otherwise, I guess I'll have to hack around with Upgrades some more, and get some fairly hefty plugins (subdirectories and all) working within the /upgrade-plugins framework.