As one of today's Kindle Daily Deals,
The Collected Stories of Eudora Welty is $1.99 at Amazon US. Not price-matched yet that I can see anywhere, and Kindle Daily Deals often aren't, but you never knew. The Whispersync-ready audio is also $1.99 after you buy the e-book. Whispersync discount prices are often lower as well when books are in the Daily Deal, so it's worth buying the audio now if you're going to.
For those who, like me, prefer their collected editions complete, I'll add that this does contain all Welty's short fiction: anything published later is entirely reprints.