Amazon.com offers the QNAP TS-431+ 4-bay NAS for Small Offices & Home Offices for $ 219(List Price $ 409).
Free shipping.

Features: Build a private cloud-based notebook to share with colleagues and friends with the Notes Station 2.0 and Qnotes mobile app; Organize & manage files and backup tasks in one centralized location; Full NAS encryption by volume-based technology and hardware acceleration; Synchronize files between computers, laptops, and mobile devices; Create a 24/7 surveillance center for your home/small office.