Or fly Southwest, which only charges the fare difference*, but no change fee.
Otherwise, suck it up and pay.

Note that refundable tickets tend to be much more expensive than non-refundable, maybe more than the change fee. If your plans are shaky and you think you may change multiple times, refundable/fully flexible is the way to go. If they're pretty set, it may still be cheaper to buy the non-refundable fare and change once, or even twice.

*Pretty much every airline in the US charges a fare difference, although not all charge a change fee.