Upload & Sell: Off
We're talking numbers in excess of $1,900.00 to he can grab a little more frame n soccer.
The D3s is a keeper.. The subtle differences one sees between a D800(e) or D4 are insignificant all things considered. You have 4 choices here.
1.. Step up to better glass. I shot with a 300mm 2.8 ED-IF (older) and on my D3s, it has no problems tracking in constant mode...on any sport.
2.. Pop a 1.7 on that 70-200, crank up that ISO and call it good.
3.. The older 300's and a 1.4 or 1.7 work too. Slows the focus down a tad, but you'll adjust to the feature set just shoot.
4.. Do what everyone is suggesting. Sell your wife, kids and car.. Invest in all new kit.
But the idea of using a D800 for any sport is really kinda out there.. Fast memory notwithstanding, the buffer is too limiting. There's a time and place for everything, this isn't it.