My undergraduate advisors really discouraged me from pursuing an MA but did recommend I take a year or two off before applying to PhDs. I was told that MAs are primarily useful if you didn't have the opportunity to pursue original research during your Bachelors. Obviously every profile is different but I do think that the cost of MAs, and the fact that your PhD program will probably expect you to complete their MA coursework anyways, makes them unappealing IMO.
Take this with a grain of salt - I'm still waiting to hear back from most of the programs I applied to. But this was the advice I received from faculty with undergrad & graduate advising experience and in a pre-doctoral fellowship. No one in my fellowship pursued a MA before beginning their PhDs and all were admitted to their top programs. Hope this is helpful!
