We'll be announcing a secondary lower rate for calls forwarded to SIP addresses soon.

With that being said, the focus of the service will still be PSTN forwarding since 99% of our customers that use it don't even know what SIP is and are just looking for numbers in other cities, etc.

If you're just looking for incoming SIP only service, there will definitely be cheaper options out there since our Express service isn't really meant to compete in that area.