As a new user, I am a little confused about pricing, users and extensions. I would like to have a desk phone at home connected to my business. I already have a phone that I could use for that purpose but I am unclear if it would cost more. I would be either using my office phone or my home office phone. I don't have the option of logging in and out. I don't think my phones (Cisco SPA-504G) support that feature. Can I just create an extension and plug it in at home?