I have 500 Pokémon and K-pop cards. I talked to a pro assessor to see if I made a bad investment.

• I have a collection of around 500 Pokémon and K-pop photo cards.

• Some cards are worth a lot of money, and I wanted to put a value on mine.

• A professional card assessor gave me some advice about card investing.

Hello, my name is Cheryl, and I'm a card-collecting addict.

In the last year, I've gone down the rabbit hole of collecting binders full of K-pop photo cards. I've also dabbled in collecting trading cards, mainly from Pokémon and Magic: The Gathering.

Cards can be a million-dollar investment: Logan Paul sold a graded Pikachu card for more than $16 million in February.

I wondered — have the hundreds of dollars I've spent on these cards been a complete waste? How much is my collection worth? Would I be able to flip $1,000 worth of cards for $10,000?

I took my cards to Johnathan Lim at Singapore's Oxley Grading, a business that helps collectors assess cards before they decide whether or not to send them in for grading at businesses like PSA and CGC.

Grading tells potential buyers how much it's worth, and pegs it against the market price of similar cards. The card also gets put in a protective slab to preserve it.