It appears to me that Google is simply sponsoring the deployment, and did not build and will not actively manage the installation. According to the coverage map [1], technical support is provided by Sky Packets, a company that plans, builds, and maintains wifi networks in municipalities. Also, the Chelsea Improvement Company's webpage [2] says: "Google's sponsorship paid for the capital cost of the network."
IMHO that pricetag is very good. Consider backhaul costs, upgrades and other maintenance, monitoring, etc. All covered by about the equivalent of a 1/4 NY sysadmin salary.
Once the wifi nodes are installed, they are completely solid state so the management should be completely remote except occasional failure which is just a simple swap replacement?
So again, why $45k a year in operation?
Four nodes per block X 13 blocks = 52 units? (guessing)