This may not be a very recent study. Published in October 2009, the ITIF Broadband rankings study looked into the average broadband speeds and cost in countries with the fastest internet connectivity. The results are interesting. One of the critical take-aways is that the price of broadband is, more often than not, proportional to the speed offered. That makes Japan the fastest and cheapest in terms of broadband connectivity.
Here is the average cost of broadband (for 1 Mbps per month in USD) in the ten countries with the fastest internet connectivity
1. Japan : $0.27
2. Korea : $0.45
3. Finland : $2.77
4. Sweden : $0.63
5. France : $1.64
6. Netherlands : $4.31
7. Portugal : $10.99
8. Canada : $6.50
9. Poland : $13.00
10. Norway : $4.04
USA is the 15th country in the list and has an average broadband cost of $3.33 for 1 Mbps per month.