In the west, the economics are stacked against trains and usually require government subsidy to run, sleeper trains are some of the most expensive since they us

In the west, the economics are stacked against trains and usually require government subsidy to run, sleeper trains are some of the most expensive since they use lots of staff and carriages that are not much use for anything else. This company is trying the luxury angle so that people would pay more than they might for a "normal" train and therefore the business might be viable. Lots of people do use charters and luxury trains so it might not be crazy but the difficult part will be not running too many services to cost money but not too few that they are not useful for the traveller.