The holy grail
Here it is - the most desirable collectaꦺble videogame in the world. Yes, even more th🍸an a copy of GoldenEye for Xbox 360.

Nintendo World Championship 1990 - NES
In the early 1990s, there were several gaming championships which used multi-game cartridges. The idea was that gamers would play three games for a limit🌠ed amount of time, then the best overall score would win.

This grey NES cartridge was given out as prizes to 90 runners-up and so is extremely collectable for Nintendo enthusiasts.

Currently there's a limited edition reproduction of the cartridge going on eBay – we're not sure how valuable a reproduction cart is going to be, but there were apparently only 22 made in its initial production run, so we'll see. At the time of writing it's up to $51, but it could well go much higher. But if you see anything with Nintendo World Champi🔴onship 1990 written on it𝕴 at a boot sale, it's probably worth the risk of buying it, just in case.

But the story doesn't end there for the Nintendo World Championships cart. While there were 90 grey cartridges, there were a further 22 gold versions, which were given out to winners of a Nintendo Power competi🧜tion. These are the holy grail - especially as some remain 'unfound'. They could be in your loft.

One MyEbid auction for a job lot of 24 NES carts containing the game ended at $21,400. Apparently the listing owner's son had died in Iraq, so he was s🃏elling off some of his things - and didn't know what he had. This surely puts the value of the cart at around $20,000 (£10,000), as there was nothing else of note in the titles for sale.

One definite, confirmed price cജame up recently when a collector named James Baker paid $15,000 for one of the gold cartridges. You've got to be pretty dedicated to spend $15,000 on a game. When UK games mag Edge asked him what his friends thought of his purchase, he told them: "The ones that ꦜaren’t into games, well, either I don’t tell them or when I tell them they think I’m nuts. But I don’t blame them."

Want to see what all teh fuss is about? C🦹heck out this footage of the game in action:

Want to start collecting?
If you're serious about collecting, t♋hen we've got some pointers for you. These are:

1) Always buy complete versions of games
That means box,🔜 instructions a🃏nd disc/cart and especially any extras that came with it like music CDs or game maps.

2) Condition is king
A single crease or tear is en✅ough to deter many would-be buyers from parting with their money, so make sure yo🐬u keep your games in the best possible condition. Seriously, don't even open them, let alone play them. Sounds daft, but just remember that factory-sealed Mario 64 up there.

3) Don't buy re-releases
A Plat🎃inum version of Final Fantasy VII is less appealing than the original black versiꦉon. That's just the way it is.

4) Go for the unique
Got something signed by the lead programmer?🌄 How many other people are going t🦋o have that?

Well, weꦚ're off to a car boot sale to have a rummage around. Don't even think about tryi🌺ng to beat us to that gold NES cartridge. Even if it is only Zelda.

Of course, if you do come across anything rare and exciting, do let us know in the . After all, there's bound to be pl൩enty out there that nobody even knows about yet...