In case this is helpful to others here - I want to add that MRDVR physical box itself only costs more if you actually have other DVR's in your home. Specifically - I did have a second DVR in my home, decided to disconnect that TV and return the DVR. It was NOT necessary for me to return my MRDVR box; the multi-room capability was just terminated by Verizon (no impact on equipment in my home). And billing was adjusted so I'm now just paying same as a single regular DVR.
That was great - since I didn't have to lose the recordings I had stored on my MRDVR unit.