Prudence and the Estate Tax

Sometimes I have the sinking feeling that just about all policy issues (other than abortion and same-sex marriage, perhaps) can be too easily shoe-horned into the realm of "prudence" despite the wealth of wisdom offered by Catholic social teaching.  In an attempt to bolster my flagging confidence, can we agree that the existence of the estate tax -- putting aside questions of rate, when it kicks in, etc. -- is supported by CST, and perhaps more strongly, that its elimination would be condemned by CST? 

Let's assume, for the sake of argument, that the estate tax were to apply only to estates of $100 million or more, and that its rate was 5%.  At these numbers, it is difficult to discern significant incentive-based consequences in terms of wealth creation and productive behavior.  There would still be calls for its elimination, of course, but they would run along the lines of "It's mine -- hands off!"  Such bright-line principles, lacking a functional justification relating to the common good (or the option for the poor, solidarity, etc.) appear to me to be directly opposed by CST.  And unless we have in mind a fixed maximum amount of revenue that the government should be empowered to collect, it doesn't make sense to speak of balancing the estate tax's elimination through an increase in income taxes, for example (which could bring incentive-based consequences).  Eliminating the estate tax would simply reduce society's collective capacity to pursue the common good with no clear functional benefit.

Any dissenters from this view?  And is the dissent itself grounded in the norms of CST?

Rob