Hmm... is it a good card...??

Also, if you could let me know the market price for Mega Rayquaza... haha

Aquastar EX shows stable performance as a first evolution, so it's quite decent. Mega Rayquaza is a very rare top-tier card, so keep in mind that its market price fluctuates a lot, hmm!

It depends on what you consider a good card, though.

When the Pokémon Trading Card Game first came out, Aquastar was a Tier 1 card, dealing 90 damage with 2 energy for a Stage 1 evolution and having no retreat cost. However, with many better-performing cards released recently, its value has decreased compared to before. Still, it's a ★2 card and not completely bad, so it holds some value.

Only Pokemon is bad. The cards are good.