Yes, you are correct. However keep in mind that you would have to be on edge to get the $140 pricing. Once you are not on edge, it moves up $20 per line .
yes, I specified that in my post.
So let's say both users want to get a GS5, which would be about $25/mo on Edge = $600 x 2 = $1200.
They are saving $20/mo by moving to More Everything + Edge and getting 6GB more data per month as well as unlimited minutes instead of 700, which may or may not be important to them. So over the course of 24 months, they save $480. Deduct that from their $1200 phone costs and that is $720 for both phones.
If they stay on a nationwide family plan, their phone costs would be $230 x 2 = $460 so the would still come out ahead by $260 and in many states there would also be a significant sales tax savings. But of course they would not have unlimited minutes and would have 6GB less data, which may or may not be important to them.
If your family has unlimited minutes on a nationwide family plan then the situation would favor the More Everything + Edge.
So people just need to look at their needs and price it out but don't forget to include the phone costs including the sales tax.