A retired decorator in Woking kept 42 sets of Pokémon cards in his loft for fifteen years, and they are going to auction at £250,000.

A retired decorator from Woking who has asked not to be named is expected to make a quarter of a million pounds next month from 42 complete sets of Pokémon cards, the Farnham Herald reported on Saturday. They spent about fifteen years in his loft.

He began buying them in the late 1990s, when his son was collecting cards and swapping them in the playground, and he told the paper that he thought they looked nice and wondered whether they might be a good investment.

The seller in Malaysia

He found somebody on eBay in Malaysia who dealt in complete sets, bought a couple of things from them, and was then asked whether he wanted a full master set, because the seller had two or three of them for every issue. Buying a set whole, he worked out, was cheaper than buying sealed packs and hoping the cards inside would eventually add up to one.

His first set cost him £300, the Sky Ridge Charizard set, and Ewbank's have put it into next month's sale at £20,000 to £40,000.

Every set went into a Pokémon ring binder, still sealed and in mint condition, and when his son stopped being interested the lot went up into the attic, where it stayed. The son had cards of his own to play with, so these were never opened.

He had his own cards, but he never got to touch these, I'm glad to say.The collector, to the Farnham Herald

The valuation

He read a story in his local paper about a single Pokémon card going for more than £6,000, realised he owned several of the same kind, and took a sample down to Ewbank's Auctioneers at Send to have them valued.

When we saw what he had, all in mint condition, we couldn't believe it, or the fact that he had no idea what they were worth. When we then discovered that he had 42 such sets, our jaws hit the floor.James Spooner, head of trading cards at Ewbank's

Spooner told the paper it is easily the most valuable collection the firm has handled, and that the total could reach £270,000 hammer. Ewbank's has run dedicated trading-card sales for five years and taken more than £1.1 million across all of them.

I know people always talk about finding treasure in the attic, but in my case that is literally true.The collector, to the Farnham Herald

The other Surrey attic

This is the second Pokémon collection to come out of a Surrey loft and into the same auction house this year. A teacher, Andrew Braund, went to Ewbank's in April with cards he had left at his parents' house for twenty years, and three of the rarest sold on 16 April for £32,800 between them, which he put towards marrying Rachel Moseley in August.

The decorator's 42 sets go under the hammer on 21 October, in a single-owner sale called Pokémon: A Decade of Masters, 1999 to 2009.