Why not set it up in your spreadsheet this way?

Your set up seems so complex. And adding 100 years seems like it
will be too many characters for your formula.

A B C D E F

Year Cost Cost 2 Cost 3 Total
0 2000 225 300 525 =sum(C1:E1)
1 2001 125 225 350
2 2002 125 300 425
3 2003 125 225 350
4 2004 125 300 425
5 2005 125 225 300 650
6 2006
7 2007
8 2008
9 2009
10 2010
11 2011
12 2012
13 2013
14 2014
15 2015
16 2016


Dan