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OfficeMax.com has the Panasonic KX-TS4100B 4-Line Integrated Corded Phone System for $20.
Final Price for this deal: $20 + shipping. Free in-store pickup.

Description:
# 24-Digit Per Station Dialer Storage Capacity - perfect for international phone numbers
# 32 One-Touch Memory Buttons
# 6 Number Redial Adjustable Handset Volume Control
# 8-Step Speakerphone Volume Control
# 4-Step Ringer Volume Control plus Ringer On / Off
# Convenient Line Selection - Group / Prime / Auto Intercom / Voice Paging / Call Transfer Hold / Mute / Redial / Flash Selectable Do Not Disturb mode
# Real Time Clock AM / PM Format
# Wall Mountable or May be used on Desk or Table
# 2 Desktop Angle Choices
# Power Outage Operation (Requires Battery)
# 2.5mm Headset Jack for adding an optional phone headset
# Bilingual Menu Support (English / Spanish)
# Can work during Power Outage (requires battery)