Marisa,
We have recently networked our computers here in Athens County, and found it to be very nice to share Internet service through our DSL connection. What about your building lends itself to not being easily wired for service between floors? The router cost us about $60, and the requisite Ethernet cords were not too pricey either. You might look to see if a local university has some spare cable you might be able to get from them. Our Web site is hosted free of charge by our DSL provider, and we get pretty good service from them. If you can find a way to get the routing between the floors, this might be an option you'd try.
Jim Sturgill
Executive Director
Athens County Historical Society & Museum