Definitely worth the investment
But, because the condition of cards is just as important as how rare the card is, most of the cards from back in the day are not worth very much
The Best Way to Get More Wildcards Unassuming Sage | Illustration by Michele Giorgi Basically, the best way to get wildcards is to just open packs
Colresss Experiment is there to help you expedite cards in your Lost Zone and will often be the most played Supporter card for you in each game
The other option is to take advantage of the direct damage, which is good in its own right to either finish off a damaged character or get them within range to be banished but also works with the likes of cards that benefit from being damaged - such as Scroop, Backstabber - that benefit from healing damage, like Rapunzel, Gifted Artist, or from damage being dealt: like Beast, Relentless.