"...canon 1277 lists some cases where the bishop’s okay is not enough. For those financial actions which are of major importance, the bishop is required by law to consult the diocesan finance committee and the college of consultors. And for acts of extraordinary administration, the bishop actually needs their consent."
"...what constitutes “major importance”?
"...canon 1277 observes that Episcopal Conferences are to determine what will constitute extraordinary administration in their respective territories."
"Expenditures requiring consent can of course be blocked, leaving a bishop who’s eager to make a large purchase legally out of luck. In short, for extremely large purchases, a bishop cannot act entirely on his own—if he does, he is violating the law."
"...if a diocesan bishop unilaterally spends a sum of diocesan money so high that he was required by law to run it by his finance council and college of consultors first, he shouldn’t be surprised if Rome calls him to account for this. Since the numerical amounts involved aren’t a matter of subjective opinion, there isn’t necessarily a lot of room for him to argue."
"Bishops have a lot of power in their dioceses—and that’s the way it’s supposed to be. But when it comes to spending diocesan funds, there are some strict legal limitations on their buying-power. Canon law provides diocesan bishops with plenty of leeway when it comes to their purchasing decisions, but nonetheless there are clear boundaries which they cannot cross without the advance consultation and/or approval of others. If they do, they may be forcibly reminded that they are ultimately under the supreme authority of another Bishop, here in Rome."