If you're looking for an even more cost-effective IP phone option, these refurbished phones from Cisco may be a solution.
All Cisco refurbished phones are refurbished by Cisco and include a 1-year 8x5 NBD (Next Business Day) SMARTnet contract. This means you can download Cisco SIP software at no charge, have 24-hour access to Cisco Technical Assistance Center, as well as access to operating system software updates.
Unfortunately, these refurbished phones do not include Cisco Call Manager or Cisco Call Manager Express licenses.