The ooma Core VoIP Phone System with No Monthly Phone Service Bills is on sale on Amazon.com for $229.99.
ooma is VOIP service that offers free US calling and basic service with their device. Besides making money with the hardware, the company offers the ooma Premier service which for a fee of $99.99/year gives you additional services like: Instant Second Line allows you to make or take two simultaneous calls from a single phone number.
Message Screening allows you to listen in as the caller is leaving their message. Send to Voicemail allows you to transfer a call to your voicemail.
Voicemail Forwarding lets you forward voicemail so that you can listen to it from your favorite email program.
Do Not Disturb allows you to roll your calls into voicemail without ringing your phone Personal Numbers allows you to select additional phone numbers in any calling area in the US.
More details on ooma and Amazon.com.