That's really not necessary, but it's not a bad way to go either. A couple things I would like to point out though: As was mentioned by a few people, VPN services can be both device specific or applied to your router. Many VPN clients allow you to install their software on multiple devices with one subscription fee. Mine allows five, so all my devices are covered for a few bucks a month. I think this is simpler and cheaper than installing a secondary router. Plus if you install on your mobile devices, you can use the VPN anywhere on any WIFI connection, which IMO, is incredibly important when trying to bank, email, etc while you are not at home. I wouldn't recommend mobile banking when using public hotspots. You cannot do that if your vpn is only on your router. In addition, even when you are at home, the info you send through your router is not secure between your home computer and your router. It is only encrypted between your router and the proxy server. This could pose a security threat potentially.

Enabling your vpn on individual devices allows you to keep your computer use relatively confidential, while allowing your tv to stream through your ISP's server normally. That said, Netflix hasn't banned every single IP address and you can actually still watch it at a number of different IPs if you do decide to install it on your router. Plus, watching Netflix with a VPN allows you to watch shows and movies not available in your home country (if the IPs of those servers aren't blocked yet). Also, you can simply turn the VPN on your router or device off if you want to stream netflix normally.

Just a few things to keep in mind.