Originally Posted by
btonkid12345
Do you know the price of your new flights? It will be simple: take your old fare for the outbound segment, subtract the new fare and change fee, and the difference is the cost. The new fare should be available on Delta.com.
Right - just to add some explanation for OP, the rules of most fares state that if you're changing the outbound segment, you basically have to purchase a new ticket at whatever the current price is. You'll obviously get the credit for your existing ticket less any change fee.