This is very cool to see. However, you shouldn't have accounted for the splits like you did (I think you had it right the first time you did it). Prices you find in databases/charts for stock prices are already split adjusted.
For example, Apple PowerBook G3 250 (Original/Kanga/3500): Price stated at $5700 released on 11/10/97. On 11/10/97 AAPL closed at $18.37/share. If you spent all $5700 you would have 310.3 shares (assume you can buy partial shares). On/around 6/5/2000 the stock split so you would now have 620ish shares. On/Around 3/28/05 stock split and you would have 1240ish shares. Multiple this by the stock price ~$270/share and you have ~$330,000. As someone already pointed out, you should not take into account inflation because the $330k is the amount you have have in the bank TODAY if you had bought the stock back on 11/10/97.
If you look at the stock chart you will see the price reports on 11/10/97 for AAPL is $4.59/share, this accounts for the split (It was actually $18.37 on that day, but divide by 4 because of the splits and you get $4.59). You can see http://finance.yahoo.com/q/hp?s=AAPL&a=10&b=1&c=... for details about this (You will notice a "close" column and "adjusted close" column. The "adjusted close" is what you will see on all the charts, but "close" was the actual close that day. This is done to avoid massive jumps on the charts that would make them less useful.
Hope that helps, and once again, this was a really cool thing to see, it really puts some things in perspective.