We used a relo company (Sue at Relocation Solutions was amazing) and I can tell you that for us it was totally worth the one month's rent.
We are a family of 6 and did not have a house hunting trip due to visa issues for our son. She not only previewed he properties, she set all the appointments, drove us everywhere to see them, negotiated the rent on the one we liked, took us to set up our bank accounts, helped with school enrollment for the children, and she helped us unpack, fed us lunch and entertained the kids all day on the day our goods arrived. For someone coming into a country and needing to get all of this done on a short time frame she was a lifesaver!