No, the price will not be €100. You need to pay more. (sigh)
The total mintage is 20,000 indeed; the lowest figure of all the euro commems so far. Well, Monaco can only issue 1/500 of the French annual volume, so they cannot issue millions of those. But even if you buy the coin in Monaco (4,000 will be available at the exhibition "Les Annees Grace Kelly" at the Grimaldi Forum), you pay €110 or so. Quite a lot for a €2 coin.
Dealers elsewhere charge more of course. Tresor du Patrimoine, for example, wants about €150, Muntplaats even charges almost €200. Now the coin was issued only a few days ago, so maybe prices will go down a little once the piece is "widely" available. But don't expect much in that regard.
http://www.tresordupatrimoine.fr/in...07_grace.gif (pre-sale ad, but the current price is the same) or
http://www.muntplaats.nl/item.php?p_id=8123Those who decided to collect only the euro coins from the EU member states (and "ignore" the three non-EU euro countries) are better off now. They can save those 150-or-so euros and spend them on more interesting pieces instead.

Christian