Generally datacenters are built in less dense areas that already have low taxes. So the cost to "buyout" the town council (i.e. "We will cover 75% of your municipal budget") is a rounding error for the datacenter builders.

Its states and federal usually offering tax breaks. But at least on the lowest level, it's pretty cheap to buyout a rural town, and that's why you get these town councils voting 9-0 to approve the projects before anyone even hears about it.