As for the VPN issue. Yes you ARE being oversold. You did not say if the BCM will be connected to a new internet circuit or your existing internet. I am assuming all will use your existing. In that case how will their VPN router connect into your network and how will that provide anything different than with your existing VPN router provides?

Either they don't know what they are doing or they are trying to bilk you for money you don't need to spend.

Just ask lots of questions from them and others until you are clear about how it all will work.

Also please be sure to get your IT person involved. As one from the IT world its stuff like this that makes our life more difficult, when we are not asked beforehand about how it will impact the network.

Case in point... Copier installers plug their machines into the LAN, grab a DHCP IP address, and assign it as static. Uh why won't that work.. Because you are an idiot copier installer who knows nothing about networks!