How much is a 10000 dollar gold certificate worth?

You need to give us the year (and possible letter) of the series.

The most common 10,000 gold certificates are those found with a 1900 series and have holes punched into them. These holes are evidence that the gold certificates have been "canceled", that is someone previously had redeemed the bills in gold coins therefore the bill is no longer legal tender. Such bills in absolute perfect shape are worth about $7,000-8,000 or so. However, since most were found in a burning building in 1935, many have burn marks or water damage and are worth substantially less. Either way, if you have any high denomination note, it is best to take it to a coin dealer or expert in paper money for a professional evaluation as some can be worth quite a bit.