For the first look it seems to me that dax and the spx500 have a very strong positive correlation an in my brokert the cost is lower with the ger30 (dax).
The Base date for the DAX is 30 December 1987 and it was started from a base value of 1,000. The Xetra system calculates the index after every 1 second since January 1, 2006.
