Especially considering that the landaulets normally list for around $1.3. In that respect yes it's definitely overpriced.
Another way to look at it is that the Maybach 62 that it's based on can be bought for under $400,000...so again, overpriced.
I suppose the extra price might be in the details and the materials used (Paintwork, granite trim and probably the best leather money can buy) Also getting that convertible roof to work probably took a decent amount of R & D.
I'm also wondering about inflation as well..... the old 600 landaulets were so expensive that supposedly they never even had a list price. In the mid 90s the Mclaren F1 was the worlds only million dollar super car....now there are over a dozen out there. $1,000,000 doesn't buy as much as it used to.
Either way given the choice I would take a normal 62 but I think the landaulet is gorgeous....particularly the interior.