Forget rooting around in your attic for long-lost valuable items to sell on eBay – these days it’s all about sourcing priceless products from inside your fridge and kitchen cupboards.

Hundreds of discontinued or soon-to-be-discontinued food items are selling for tens, and even hundreds, of dollars on sites like eBay and Amazon, as foodie fans try desperately to snap up their favorite items before they are gone for good.

For example, Crystal Pepsi, the clear cult soda that was taken off shelves in 1994, was among the highest-priced nostalgic nibbles at a whopping $500 for a trio of unopened two-liter plastic bottles.

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Discontinued products: Crystal Pepsi was discontinued in 1994, but three unopened bottles can be bought on eBay for $500

Discontinued flavors: Frosted Hot Fudge Sundae Pop Tarts are selling on eBay for $103.09 per pack

But the soda is far from the only kitchen staple that is selling like hotcakes. Nestea Decaf Unsweetened Iced tea is listed at $145 for three jars, and Surge, the citrus-flavored drink released by Mountain Dew to compete with Coca-Cola back in 1996, is another highly coveted item.

Surge was discontinued in 2003, and brought back this year to be exclusively sold by Amazon.

But that hasn’t stopped fans from flogging it on other sites. 'SURGE is the bolder citrus soda that fuels a familiar rush from back in the day. Don't miss your chance to get a taste of your childhood,' one eBay seller - who is offering 12 cans for $89.99 - wrote.

And despite the shockingly high prices, these enterprising sellers don’t seem to be short of buyers, many of whom will go to great lengths to get their sugary fix. Buyers of Betty Crocker's Rainbow Chip frosting were so devastated after General Mills announced that it would be discontinued that they set up a Facebook page where more than 16,000 fans called for a comeback.

They were thrilled when the company announced that it would be back in stores beginning May 2015, but eagle-eyed shoppers have noticed that Rainbow Chip has remained incredibly difficult to find. The news of its re-release has seen sellers offer more sensible prices online, however; it has dropped from $30 per tub to around $12.99.

Selling out: Crispy M&Ms were a fan favorite, and though Mars has brought them back, some shoppers report that they can be hard to find

Feeling nostalgic: Surge was introduced by Mountain Dew in 1996, but taken off shelves in 2003

Katy Perry should be happy: The pop star was so frustrated that she tweeted General Mills a few years ago, saying: 'YO WHY WOULD U DISCONTINUE RAINBOW CHIP FROSTING? WHAT DA HECK AM I SUPPOSED 2 PUT ON MY FUNFETTI CAKE? HOW CAN I TURN 30 NOW?'

The 80s breakfast staple Pop Tarts are also popular. Though they are still widely available, many of the esoteric flavors such as Frosted Hot Fudge Sundae have been taken off the shelves. On eBay, a box of the pastries is currently $103.09.

Some sellers make it clear that their products do not expire until 2016, others will clearly be feeding on nostalgia rather than the contents.

A 1980 Ghostbusters-themed tin of now defunct Hi-C fruit punch is listed for $89.99 - despite the fact that the bottom of the can is open.

Fans of Yummy Mummy, a monster-themed breakfast cereal that joined better known characters Count Chocula, Boo Berry and Franken Berry in the 80s but was taken off the shelves in the mid-90s – can find an unopened box from 1989 for sale on Ebay for $190 or best offer.

Brand recognition: Altoids Mango sours are available on eBay for $55

That's a Hi price! This can of Hi-C Fruit Punch is selling for $89.99 despite the fact that the bottom is 'opened'

Old school: Some buyers are even picking products that are clearly inedible, such as this box of Yummy Mummy breakfast cereal from 1989

Whoever dares to open it should find the original bat marshmallows inside.

Some items that have been discontinued and re-released continue to command high prices due to the difficulty in finding them.

Currently, crispy M&Ms - which Mars stopped selling in the U.S. in the mid-90s - are available from Australia for around $90. The chocolate balls with rice crisp center were re-released in January of this year, but are still hard to find.

Buyers rush in as soon as companies announce that they are discontinuing a product, and the price fluctuations can be extreme. Currently, a tiny tin of Altoids Mango Sours is up for bids at $57.

One seller of Cinnamon Tic Tacs says he is offering the red candies from his 'private stash,' at $145 because he predicts that the miniature mints will soon 'become harder to get than Cuban cigars'.

Dessert afficionados will doubtless remember the Great Twinkie Scare of 2012: After Hostess went out of business in November 2012, fans of the cream-filled cakes went into a frenzy, and online auction prices reached a high of $200,000 for a single box.