It may be worth noting that sales data on these will probably be quite misleading as PSA used to slab these with the cards facing backwards (this applies to all of the Battle E sets, but I posted a thread specifically about the FireRed & LeafGreen set a few days ago here: www.elitefourum.com/t/the-6-2-wannabe-charizard-cards-of-firered-leafgreen/32655/1). I imagine a lot of people who bought those cards recently from PWCC did so under the belief they were buying a Charizard, Blastoise, Venusaur or Pikachu card rather than a card which simply featured those Pokémon on the back.
From what I can tell PSA started grading these back in March 2019 and only corrected this when certs hit 48XX - people right now are only just getting their mid-2020 bulk submissions back with 49XX certificates, so I imagine the vast majority of the current Battle E cards graded show the back instead of the front. On top of that, PSA are more lenient when it comes to the back of the card vs. the front, so presumably the grades on all of these backwards cards are going to be a little questionable (though that shouldn’t be too extreme).
To put that into a bit of perspective, a seller recently sold a set of PSA 9 correctly-slabbed cards from the set which all sold for around $40 - plenty of them didn’t receive any bids, either, Meanwhile the PSA 9 price of the incorrectly-slabbed cards tends to be anywhere from $80 to $180 from what I can see. I imagine it’d be difficult to discern any decent pricing info from these cards without first knowing how the card was slabbed.