Right now it's the wild wild west in getting product without paying 2-3x retail. Your best bet is getting lucky when you walk into Target or
Walmart while they're restocking their trading cards section. Gamestop will be releasing their inventory this Friday but it would seem they will also have low inventory like everyone else did.
We have a small wave hitting local gaming stores in October for this set before a big reprint wave hitting in q1 next year. So, if you have a card shop around you, you can ask if they are receiving anything in October but the first set will be hard to get until next year.
A larger print run is rumored for the next set that comes in November/December, so that set might be more readily and easily available than this first set but we will see.