Both cards are currently live on eBay and about to end; Mewtwo suffered fluctuations during last few years, it used to be worth Over 1500; then it plummeted to around $600 last year and now seems like its going to surpass $1000 once again.
As for Charizard, a 1st Ed. PSA10 Copy was obtainable for U$S2300 or less during Sept. 2019 and is now over $3300.
These seem to be, either huge increments in their value or just a sequel of the rampant shill bidding on WOTC 1st Ed Products that has been going on lately.
I sold my shining mewtwo 1st ed psa 10 for over $1k a couple months ago,
And consistently had offers over $800 over the week it was listed, not sure about shilling because I havent kept up with it. Hopefully not, but seemed people werr pretty comfortable to pay near $1k for it a couple months back
Those prices aren’t completely out of the realm of possibility. 1000 for mewtwo and 3300 for charizard. However I think a lot of us are just skeptical seeing as how rampant shilling appears to happen these days. As I type this there are about 50 minutes remaining till the auctions end. Lets see how this plays out… *(eye emoji eye emoji eye emoji)*
Im quite sure i know who won mewtwo; so i guess Mewtwo wasnt shilled at all. Not sure about Shining Charizard going for U$S3500 and almost doubling the value in less than 1 year.