I bought a real good camera on Amazon for about $20 (later found out that my son't police force cars all use the same camera). I then purchased a 7" video playback screen for about $20 as well. I purchased cable to extend the cameras cable and hooked it into my truck's wiring so that it turns on automatically when I shift into reverse. I also have it wire to a switch so that I can turn it on manually at anytime. So, I think I have about $75 into the whole setup and I've been using it for about 8 years now. It works great. The screen I mounted above my rearview mirror.
Early 99 F350 4X4 CC 7.3 Auto. A.R.E. Topper, bed carpet/bench inserts, Rhino grill guard, AIS w/sleeve, Fuel filler mod, GOS headlight harness, 02-04 Headlights, Rancho HD stabilizer, 06 Telescoping/heated mirrors with C-Btr Mirrors, Hella FF1000, Htr Bypass valve, front receiver hitch, Quadzilla XZT gauges, ITP Pre-pump/In-tank mods, Pioneer P5000UB w/XM radio, 4 Infinity Kappa 682.7cf, Fumoto valve, FIAMM Highway blaster horns, SS HPX, IDM mod, DP F5 (Stock,Drive-thru,60T,80E,120,80E-Mountain,1200), Walker BTM, RR, Dieselsite BRV, BTS Tranny (2nd one :-), 31 row tranny cooler, Bilstein shocks, Amsoil bypass oil filter, Stancor HD Glow Plug Relay, billet thermostat housing, front & rear parking cameras, Aux reverse lights, Heated Seats.
Security: CrimeGuard Alarm with remote notification, DIY jimmi-jammers, door cylinder locks and linkage removed, padlocked rear bench seat hinge, PCM, DIY "pitstop" switch.