This seems like a major ripoff especially since many phone companies offer free faxing. Cheapest solution, get a multifunction printer that can fax. (many allow you to print directly to a fax.
So at home, if you have home phone service, you can easily send faxes at no additional cost. And if you need to remotely send and receive faxes, then simply run an openvpn server on your PC, or install some firmware on your router that will allow you to run an opvpn server on the router.
you now have your own personal fax service that will work anywhere you have internet, at no additional cost.
If you only have cell service then you will need one of those smartphone docks what allow you to basically use a smartphone as a home phone service.