Are you guys totally sure the dummy esn thing is only $10/month? One of the guys in a mall kiosk tried to work such a deal for me about a year back (when I was trying to move from a Bionic to a GS3) and it ended up costing me way more than he'd said it would (at which point I undid the deal).
IIRC, he had me get on a Family Share Plan with my nonexistent cousin, who got the GS3. I kept unlimited data, nonexistent cousin had a limited data plan, and then we swapped phones -- so I got the GS3 and she got the Bionic. Of course, I had actually traded in the Bionic, so my nonexistent cousin had no phone. Which made sense, as she was nonexistent.
The problem was that, as far as VZW was concerned, my invisible cousin had a Bionic, and you can't have a Bionic without a data plan. So, in order for me to keep unlimited data on the new phone, I had to pay for a 2GB data plan on my invisible cousin's line (aka the dummy line). Which was substantially more than $10/month. I can't remember what it was, exactly, but it might've been $30 or something.
Now, this was some time ago, so things might have changed. AND the guy at the mall kiosk was a liar/moron/sack of poo, so it's very possible that there WAS a cheaper way to do it than he did it. Still, I'm very cautious when someone says it can be done for $10/month -- because when they tried to do it for me, and SAID it could be done for only $10 more than what I was paying, it could not be done that cheap at all, and I ended up having to undo the deal and give back the shiny new phone.