Interesting. From Siliconera:

If someone missed out on picking up a NES Classic Edition the first time around, a second chance has presented itself. Starting today, June 29, 2018, the plug-and-play system has returned to stores. You should be able to find it on both digital and physical retailers very soon for $59.99. Best Buy, GameStop and Target all have their listings up.

Both the NES Classic Edition and Super NES Classic Edition are expected to be available in stores through the end of 2018.
If all of that is true, then places like Amazon and Wal*Mart should be getting stock of the NES and SNES CE's throughout the rest of this year. Hopefully that means that prices for new and used consoles will drop to reasonable levels. I've already noticed a real effect on the prices at places like Amazon, where what was once $250+ is now like $80.

Also of note: GameStop listings for Super NES Classic Edition - Ships by 7/6 and Nintendo NES Classic Edition - Ships by 7/13. I guess that's how GS is going to handle orders for the next round of consoles on its Web site.