If the above statement is accepted at face value, then thought Gettysburg was a small price for the South to pay for Lee's effective and unifying field leadership over the entire course of the war.
Applying any cost/benefit analysis to Lee's overall field command performances in the wartime period, thought the benefits would far outweigh the costs.
If Gettysburg was the price the South paid for having Lee in command, then it was a price the Confederacy was willing to pay.