There are always costs to what is essentially keeping two locations open instead of only one. If they're opening a facility in a new city that space is going to cost the same whether you relocate there or not, so any costs associated with the lease will be in excess. Depending on how far away the two cities are from each other, they might need to double up on the costs of benefits. If by chance the two cities are in different states they will have additional costs for maintaining a location in two states instead of one, plus double the workers comp costs and the UI tax costs. All of these are on-going costs. They'll have phone bills in the leased facility; maintenance costs; utility costs; all over and above what they'd be paying in their full service facility.

Then since I doubt they'll be willing to let you work completely unsupervised, there will be periodic travel costs for someone in management to come out to your location, or for you to make periodic trips to the new location.

And that's just what rolls off the top of my head in the first five minutes. I'm sure given enough time I'd think of some others.