VPN actually saves the user thousands of dollars a month by reducing equipment costs and removing expensive, dedicated WAN connections. For the lower models, the VPN functionality is an optional upgrade, while for their PRO series it is enabled by default. The SonicWall has several other features that can come in handy. It can generate a report as to the most popular sites, bandwidth usage by IP address and bandwidth usage by service. You can also standup servers behind the firewall and easily configure the SonicWall to allow those services to pass through to the appropriate server.
All models come with a one year warrantee and free firmware upgrades.
These are the ones that need a firmware upgrade to do VPNs. The 10 and 50 units are limited to the number of IP addresses that they will allow to pass through to the internet. As I understand it, there is a SonicWall 5 that is awaiting general release as of this writing. The PRO series is the unit designed for the medium and larger size businesses. All units pretty much have the same indicators.