Can someone point out what is the difference?
And what for do we actually pay so much money, when supporting the iPhone with our hard work?
Is it right that I have to have the Enterprise Membership (299 USD), when I want to sell Apps for money? Or can I also sell Apps when I "only" have the cheaper Standard Membership (99 USD)?
Is there a fee every time I want to upload a new app to the App Store? Where is the hook in the Standard Membership?
The Enterprise Membership is only for enterprises - no app store distribution, but you can distribute your programs within your enterprise (ad-hoc). With the Standard one, you can put your apps on the app store but can only give out 100 copies of your program using ad-hoc.
There is no fee for submitting apps to the App Store once you have a Standard membership.
From Apple:
The standard plan does NOT allow distribution to iPhones (except a few development phones) outside of the app store.
The enterprise plan does NOT allow distribution to iPhone via the app store, but does permit developers to deploy their own programs within their own organization without designating those phones as 'development' phones.
"The standard plan does NOT allow distribution to iPhones (except a few development phones)"
how many phones??
If you want to distribute both to your organization via adhoc and the public via App Store, you need to register two separate accounts. This was confirmed in an email from Apple Dev Support.