When is it ever enough - how many of these little megabits do we need?

Our 4 Mbps connection is saturated for much of the day. We had 2 Mbps last school year and doubled after that was saturated. But how much is enough? Should we ration and/or educate users that internet connection is like any other resource - you need to just open the tap enough to get the stream of water to drink from and remember to turn the tap off afterwards....
The State Education Technology Directors Association (SETDA) issued their recommendation (vision?) for the Class of 2020 Action Plan for Education with reference to broadband speed :

Key recommendations include:

In a technology-rich learning environment for the next 2-3 years, SETDA recommends:

• An external Internet connection to the Internet Service Provider of 10 Mbps per 1,000 students/staff
• Internal wide area network connections from the district to each school between schools of at least 100 Mbps per 1,000 students/staff

In a technology-rich learning environment for the next 5-7 years, SETDA recommends:

• An external Internet connection to the Internet Service Provider of 100 Mbps per 1,000 students/staff
• Internal wide area network connections from the district to each school between schools of at least 1 Gbps per 1,000 students/staff