I was looking at this NVR, really I couldn't tell you how it performs and you also need to add the drives but the Unit is under $100 so might be worth a try.
[TABLE="width: 100%"]
[TR="bgcolor: #004F9E"]
[TD="width: 200"]Model No.[/TD]
[TD="width: 205"]HK-NVR5204F[/TD]
[TD="width: 205"]HK-NVR5208F[/TD]
[TD="width: 205"]HK-NVR5216D[/TD]
[/TR]
[TR="class: table_p, bgcolor: #FFFFFF"]
[TD]Main Processor[/TD]
[TD="colspan: 3"]Hi3520D[/TD]
[/TR]
[TR="bgcolor: #FFFFFF"]
[TD]Operating System[/TD]
[TD="colspan: 3"]Embedded Linux[/TD]
[/TR]
[TR="bgcolor: #FFFFFF"]
[TD]System resource[/TD]
[TD="colspan: 3"]Multi-channel real-time recording synchronously, multi-channel real-time playback, multi-channel multi-user network operation, USB back up.[/TD]
[/TR]
[TR="bgcolor: #FFFFFF"]
[TD]Operation interface[/TD]
[TD="colspan: 3"]16 bit real color GUI interface support mouse operation[/TD]
[/TR]
[TR="bgcolor: #FFFFFF"]
[TD]Display screen[/TD]
[TD]1/4[/TD]
[TD]1/4/8/9[/TD]
[TD]1/4/8/9/16[/TD]
[/TR]
[TR="bgcolor: #FFFFFF"]
[TD]Video standard[/TD]
[TD="colspan: 3"]PAL(625 lines, 50fps); NTSC(525lines, 60fps)[/TD]
[/TR]
[TR="bgcolor: #FFFFFF"]
[TD]Image encode[/TD]
[TD="colspan: 3"]H.264(High Profile)[/TD]
[/TR]
[TR="bgcolor: #FFFFFF"]
[TD]Monitor quality[/TD]
[TD="colspan: 3"]Monitor: D1; VGA: High Definition; HDMI: High definition[/TD]
[/TR]
[TR="bgcolor: #FFFFFF"]
[TD]Playback quality[/TD]
[TD="colspan: 3"]1080P/D1[/TD]
[/TR]
[TR="bgcolor: #FFFFFF"]
[TD]Encode capability[/TD]
[TD="colspan: 3"]1ch 1080P Realtime[/TD]
[/TR]
[TR="bgcolor: #FFFFFF"]
[TD]Motion detection[/TD]
[TD="colspan: 3"]Each channel can set 192(16*12) detection area[/TD]
[/TR]
[TR="bgcolor: #FFFFFF"]
[TD]Audio compression[/TD]
[TD="colspan: 3"]G711A[/TD]
[/TR]
[TR="bgcolor: #FFFFFF"]
[TD]Bidirectional talk[/TD]
[TD="colspan: 3"]support[/TD]
[/TR]
[TR="bgcolor: #FFFFFF"]
[TD]Record mode[/TD]
[TD="colspan: 3"]manual>alarm>motion detection>timing[/TD]
[/TR]
[TR="bgcolor: #FFFFFF"]
[TD]Local playback[/TD]
[TD="colspan: 3"]support 1ch/4ch playback[/TD]
[/TR]
[TR="bgcolor: #FFFFFF"]
[TD]Video search[/TD]
[TD="colspan: 3"]Time, date, event, channel search[/TD]
[/TR]
[TR="bgcolor: #FFFFFF"]
[TD]Space occupation[/TD]
[TD="colspan: 3"]Video: CIF 4~5G/day*chs, D1 16~20G/day*chs, 960H 12G~20G/day*chs; 720P 20~30G/day*chs; 1080P ~40G/day*chs
audio: 691.2M/day*channel[/TD]
[/TR]
[TR="bgcolor: #FFFFFF"]
[TD]Video storage[/TD]
[TD="colspan: 3"]Local HDD, Network[/TD]
[/TR]
[TR="bgcolor: #FFFFFF"]
[TD]Back up mode[/TD]
[TD="colspan: 3"]Network backup, USB portable HDD, USB DVD/RW, SATA DVD/RW[/TD]
[/TR]
[TR="bgcolor: #FFFFFF"]
[TD]Video input[/TD]
[TD]4chs 1080P,4chs D1 for Storage[/TD]
[TD]8chs 1080P, 8chs 720P, 16chs D1 for Storage[/TD]
[TD]16chs 960H for Storage[/TD]
[/TR]
[TR="bgcolor: #FFFFFF"]
[TD]Video output[/TD]
[TD="colspan: 3"]1ch BNC, 1ch VGA, 1ch HDMI[/TD]
[/TR]
[TR="bgcolor: #FFFFFF"]
[TD]Video Loop out[/TD]
[TD="colspan: 3"]N/A[/TD]
[/TR]
[TR="bgcolor: #FFFFFF"]
[TD]Audio input[/TD]
[TD="colspan: 3"]N/A[/TD]
[/TR]
[TR="bgcolor: #FFFFFF"]
[TD]Audio output[/TD]
[TD="colspan: 3"]1ch RCA(200-3000mV, 5KΩ)[/TD]
[/TR]
[TR="bgcolor: #FFFFFF"]
[TD]Alarm input[/TD]
[TD="colspan: 3"]N/A[/TD]
[/TR]
[TR="bgcolor: #FFFFFF"]
[TD]Alarm output[/TD]
[TD="colspan: 3"]N/A[/TD]
[/TR]
[TR="bgcolor: #FFFFFF"]
[TD]Network interface[/TD]
[TD="colspan: 3"]RJ45 10M/100M self-adaptive Ethernet port[/TD]
[/TR]
[TR="bgcolor: #FFFFFF"]
[TD]PTZ control[/TD]
[TD="colspan: 3"]1 RS485; support multi kinds of PTZ protocol[/TD]
[/TR]
[TR="bgcolor: #FFFFFF"]
[TD]USB port[/TD]
[TD="colspan: 3"]2 * USB2.0[/TD]
[/TR]
[TR="bgcolor: #FFFFFF"]
[TD]HDD port[/TD]
[TD="colspan: 3"]2 SATA port(2*4T)[/TD]
[/TR]
[TR="bgcolor: #FFFFFF"]
[TD]Power[/TD]
[TD="colspan: 3"]12V/2A[/TD]
[/TR]
[TR="bgcolor: #FFFFFF"]
[TD]Consumption[/TD]
[TD="colspan: 3"]less than 5W(not include H.D.D.)[/TD]
[/TR]
[/TABLE]