A professional Pokemon card expert valued our childhood collections - and it's bad news for anyone who thinks they're sitting on a fortune

• Business Insider UK spoke with Roy Raftery, a trading card expert and manager of Sneak Attack Games London.
• He valued our childhood Pokémon card collections.
• He explained that the original 151 Pokemon cards will always be worth money, but how much money?

Read the full transcript below:

Harry: So we're in the Business Insider offices. We've brought in some of our old Pokémon cards, and we're gonna get an expert in to tell us how much their worth.

David: If you're like me and you're a child of the 90s, there's probably three things that you loved: It was either Power Rangers, Dragonball Z, or Pokémon.

Harry: So when I was back in school, I was probably about 8 or 9 years old when Pokemon was kind of in its heyday. It was a huge, huge phenomenon. Obviously, it was all the playtime in the playground was spent trading, and comparing your cards.

David: It's not just the value, it's kind of like the nostalgic, sentimental value of it, to be honest. You've had these for so long. It's been almost, what, 20-plus years since I've had these cards. So seeing them go will be difficult, but I think everything has its price.

Roy: My names Roy Raftery, and I'm the manager of Sneak Attack Games. The owner and I have about 30 years worth of experience in buying, selling, trading and playing all these major card games.

Pokémon has never really died down. The trading card game gives away millions in prize money every year, and most people don't know that and that's why the game is still going. You buy these cards to compete in big events that hopefully win you 10-20k.

And for the old cards, it's the nostalgia, it's fact that I want to buy the old cards so I can play how the game was when it was first made, when it was first created, that first inception of the game. And that's what continues to make cards valuable.

So I'll take a look at the cards you've brought me and we'll value them, we'll see what they're worth, see what we've got.

Alright, so the first one is the Charizard. This is what most people bring in. In mint condition, a Charizard from the first set is probably worth about £45-55. In this condition, you can see it's all bent, its got edge wear, its got chips and scratches on the card. It's probably worth under £10. This is what we typically get and I always wince when they come in because people think it's like £500-600, but really, really it's not

Everyone! If you have a Machamp, everyone's got a 1st edition Machamp. This was given away in the structure deck when the cards first came out, and it's not unique, unfortunately. So a lot of people are like: "I've got a 1st edition Machamp!" and you're like: "sorry, it's worth £2-3." Maybe £4, if it's in good condition.

If you look at this Clefairy. The front is battered, its all scratched. The back looks like it's been in a washing machine. It's peeling off here. It's because when we were kids and we had these in school, in primary school, in secondary school, we just had them in piles like this, in elastic bands like this basically. In our back pockets, just like that. And they were in our back pockets.

That's why they're like this 15 years later. They're moving, they're curved, they're warped. They're kind of falling apart basically.

Ok, Harry, the verdict is, unfortunately, I probably wouldn't take these in because of the condition. If I did buy them it would be between £7-10. Sorry mate.

So we have David's collection here, and instantly I get good vibes from it because it's in a folder. The folder looks a bit worn so he's probably had this a long time. But probably means he's kept his cards in good condition from day one.

So, in the Gold and Silver generation, which was the 2nd generation. He's got a full set of the starting Pokémon, in Japanese. This is typically something a vendor won't buy if I'm honest with you. We only buy English cards. Now and again we'll buy German or French cards at a discounted rate, but something like this is just cool. It's nostalgic, it's just cool really.

So we got David's Charizard. And it's in much better condition than Harry's. Much better. It's not curved, it's quite straight. On the back, the edges are quite clear. Not much scuff marks on them. This is...probably £20-25.

After the first couple of sets, you had the gym leader sets. And it's quite cool, they were very hard to get in England, to be honest with you. They're very short printed. Didn't really come over here as often as other places. So you've got Misty's Tentacruel and Surge's Fearow.These are cool, these are quite collectable. About a couple of quid each, but it's all this stuff that all mounts up and adds to the value of your overall collection.

So here's a good tip. No matter what Charizard card you have, even if it's one from five years ago, ten years ago, the latest set, it's gonna be worth money. Without a doubt. It's just because it's Charizard and people think like: "this is the best monster, this is the boss monster." Any edition of Charizard is worth something.

So everyone asks about Mew. Is it worth something? I saw on the internet that it was worth £1 million. Someone brought one into the shop, they thought it was worth £4000. I said, "I'm really sorry, it's not worth £4000." They thought I was lying, I wasn't.

But it was a really bad card. In terms of like, it did like 10 attack. No kid wanted a Pokémon that did 10 attack. They wanted something that did like, a 100 attack. or 80 at least.

So all in all, David's collection was much better. Retail is about £75, we'd buy it for about £35-40. Much, better than Harry's. Well done David.

Harry: So we've just had our cards valued, and it's not good news for me. They said they might not even take my cards, which I thought was a bit offensive. But what can you do?

David: Pretty disappointed. He said it was worth about £70, no more than that. And I was there thinking it was gonna be like, in the thousands you know.

Harry: Technically David beat me, but I think we both lost really.