Give the provider a real big tip if it matters to you.

I don't know if this pertains to all agencies, but I interviewed with an agency when first starting out.  It was told to me that they would pay my expenses up there (air fare/hotel), but I was responsible for paying it back to the agency out of my fees.  Of course, that agency only took a "booking fee", not the usual 50% that agencies in here South Florida get.  

That's one of many reasons I didn't sign on with that agency.

I am just starting to travel, but trying to figure in my expenses.  

Ah, the thrills of owning your own business....