To celebrate the 50th anniversary of their signature Shamrock shake, McDonald's revealed this week that they are auctioning off a high-polish 18-karat gold cup that's adorned with real diamonds and emeralds worth an estimated $90,000 dollars.

The eBay auction started Tuesday and will end March 6. As of Friday afternoon, bids on the cup reached $32,000, which might be a steal since the company says it was appraised for $90,000.

"There are 50 green emeralds and white diamonds -- representing 50 years of Shamrock Shake flavor and delicious whipped topping. There are 50 yellow diamonds in each of the Golden Arches for 50 years of being a fan fave at McDonald's," McDonald's said on the auction page.

All proceeds raised will help support Ronald McDonald House Charities in its mission to help families with ill or injured children stay close to the resources they need during difficult times.

Additionally, customers that order a Shamrock Shake and new Oreo Shamrock McFlurry via the McDonald’s App from now until March 6 will be automatically entered to win a Golden Shamrock Shake. Visit for more details.