This is the best advice you’ll find on the forum regarding investing.
An example of needing to look at every given item:
PSA 10 Hyper Reshizard is selling for $475 +/- $50 or so. It’s come down a lot from $800 when it first came out but still doing well. There are currently 256 PSA 10s (and 145 graded 9 or below) in the POP report. The set is still in print and will be for a long while.
PSA 10 Charizard ex (Fire Red Leaf Green) just sold for $530 with the two previous sales coming in at $560. It’s been a bit up and down with price but chances are you can get one for $550-600. There are 171 PSA 10s (and 444 graded 9 or below) in the POP report. The set has been out of print for about 13 years.
PSA 10 1st Edition Dark Charizard (Team Rocket) is selling for $550 +/-50 or so. Price has held fairly steady in the $400-600 range over the last two years. There are 377 PSA 10s (and 1,348 graded 9 or below) in the POP report. Set has been out of print for 17 years, give or take.
Generally, any Charizard card is a good investment because Charizard is a fan favorite and the most well-known Pokemon in the English market. The question you should ask yourself is not whether Charizard card X is a good investment, it’s which card is going to give you the best return on your initial investment. Hell, if you’ve got $450-600 to drop, there may be much better options. But I know where I’d put my money if I was investing.