"IMO if the company was serious about doing things professionally then surely they could organise travel for those where spare seating was available, offer some kind of accommodation assistance rather than just expecting people for have the savings to pay for this kind of an event."
Of course the company could organise such things. Why would they bother though? If people think buying a job is such a good idea then those people would also think paying for the interviews is ok too.
Perhaps it is all part of the interview process? They are just testing you to see just how much you are willing to fork out and what you are prepared to pay for.
Fools and their money........?