It is a very different process now than when i applied.
However I would have jumped through hoops to make sure i got to the assessment regardless of whether or not i got expenses.
If you really want the career to worry about expenses is a bit ridiculous. I had to travel to London twice as so many of us did and the thought of someone else paying never crossed my mind.
( no i wasn't earning loads of money at the time I applied i had just got made redundant and was working as a checkout girl)