I don't think that's all that unreasonable. Four-door performance vehicles that aren't limited editions tend to have pretty steep depreciation curves. If you look at the Panamera's depreciation curve as a reference, it follows that trajectory where it's at ~50% depreciation somewhere in the 3-4...
Spoke with my dealer yesterday in the Chicagoland area and he stated that they haven't received any allocations yet either, but are expecting them soon. No expected delivery dates, but said that he's hoping the VIN will get created/registered before end of year.