Found this while looking in magic auctions on ebay:
MAGIC MTG BETA UNCUT SHEETS COMPLETE SET - eBay (item 390136696840 end time Jan-27-10 16:41:20 PST)
Is that uncut sheet really worth so much?? ($20,000 selling price )MAGIC THE GATHERING
BETA (PROOF) COMPLETE SET
UNCUT SHEETS FORM (BLANK BACKED)
For The Serious Magic the Gathering Collector / Investor. This Is An Extremely Rare Item. There Could Possibly Be Others, But We Only Know Of This Set, & One That Is Currently At WOTC Headquarters.
This Beta Proof Set Contains All Of The Cards To Make A Complete Set On Three Seperate Uncut Sheets (Common Sheet, Uncommon Sheet, Rare Sheet) Please See Images. The Back Of The Sheets Are Blank (White). These Sheets Were Produced Before The Actual Product Was Released (You Could Call These "Artist Proofs"). Though It Is Difficult To Tell From The Photos (Light Glare Is A Factor), The Sheets Are In Exceptional Condition. The Power 9 Cards Are All Gorgeous & There Are Only A Few Minor Dimples On Any Of The Sheets.