Bad idea, shovels break so you get less profit.
If they auction off a golden shovel, graal gets less money from packs.  

I get around 150 gralats per shovel so its not that bad of a profit. I rarely use gralat packs, and I'm sure there's others as well that don't use them, but because a lot of people do there won't be dramatic changes in graal getting money.

But auctions would give people who DO use gralat packs a great advantage, seeing how it's an unbreakable shovel, it would be extremely expensive. I also doubt if they ever did auction off the shovel, it would be a couple not over 10 or more. Thats kind of why I said there should be a way to work for it, whether it be 100k shells to even a million. Not too many people would have it, the higher the shells it would be at. If they ever thought of selling (or whatever) the unbreakable shovel I'm sure they would have plenty of ideas how to do it.  

If there was an unbreakable shovel, it shouldn't be auctioned. There are already too many auction only items, and honestly, why is rarity important? It's just something to brag about and is unnecessary, so I think they should sell everything or sell nothing so everyone gets a fair chance (sorta?).
Well, I'm way off topic but there's my short little rant about rare items  

Posted by BEH0LD iTz SAM

I made a golden shovel a few months ago, and suggested that it was given as a melee/unbreakable shovel once someone digs up 10,000 shells, and is available to everyone. Same went for a golden mushroom dagger, golden mining pick (before they sold that wierd mining hammer or whatever) and a golden trash pic

There is a Golden Trashpick¿¡

Posted by Mystickk

I would say make it from 100k-500k shells. But that's just me make people work hard for it.

I agree, Just get it at 100,000 shells, and... Also a Golden Trashpick to get at 100,000 trash :3

I'd say, I don't really care about the rarity, Just make it like the Speedy Pizza Hat, *Cough* which I got ;), Make it like the hat, as in, work for the shovel and trashpick and mining drill to get golden power up :0, Just make like the Shovel Unbreakable, The drill which never runs out of battery and the Trashpick... well... Just be a golden trashpick ={D  

Posted by PoeticFolly

Not everything you want needs to go into the event shop.

So you choose to give stuff to people who use moms itunes?  

Posted by Yogy*

So you choose to give stuff to people who use moms itunes?

No, He's just saying work hard for it, Not to Hoard Events