The seat-specific investment costs of double-decked stock are highly dependent on the individual features and design of the train. A 100% "ceteris paribus" comparison to single-decked stock is not possible. However, usually seat-specific costs will be lower than for conventional vehicles. In some cases this will not be true, e.g. Reemtsema, Kurz 1997 made the cost estimates on a future double-decked ICE 4 shown in the following table.

Table 1: Initial investment figures for different versions of ICE

	ICE 4	ICE 4 wide-body	ICE 4 2-decked
Investment	19.2 million EURO (100%)	22.0 million EURO (115%)	25.9 million EURO (135%)
Seats	419 (100%)	513 (122%)	506 (121%)
Specific investment per seat	45.900 EURO (100%)	42.900 EURO (93%)	51.100 EURO (111%)

Source: Reemtsema, Kurz 1997

Estimates by European Transport Consult confirm that costs are usually in favour of wide-body stock as opposed to double-decked stock.