I can't work out who this is actually aimed at given the level of the incentive offered. If you're on a company paid ticket, it looks like a minefield of downsides with any possible upside being insignificant in comparison. If you paid for it yourself, presumably you wanted that cabin to begin with and can afford the cost of the ticket, so why bother giving it up for such an amount?
I must be missing something.
Your analysis presupposes that the employer either prohibits the practice, expects the compensation to be paid over or even thinks about this. If the employer either permits it or does not prohibiit it, this is a way for an employee to trade comfort for cash.
The one matter which an employee ought to consider is tax treatment. If an employer pays for something which you then sell and pocket the proceeds, that is typically income in most systems. Whether that matters for small amounts a couple of time a year is another question.