Yeah, what dborham wrote: most people wouldn't know a VLAN if it bit them on the nose, but if your your router automatically created the SSID "foo-devices" to go alongside your regular "foo" people might use it.
Like the "offer a guest network" button which, now I think of it, might already be enough.
If you do need low cost VLAN-capable gear I've had success with TP-Link switches and Mikrotik WiFi APs.