I've installed several and price is $175 if your TV right above your cable box and right above outlet. The price goes up if a new outlet needs to be run and also where you want your cable box/dvd/etc located. If you're devices are located just below the TV then HDMI cables won't cost much but if you plan on putting devices in a nearby closet or another room then the cable prices can add up quick. Since you're planning ahead check out monoprice.com for TV mount and cables. It'll be 1/4 the price of Best Buy. You may need an infrared remote if you plan on putting cable box in a closet or another room. Infrared will work through walls.
https://www.amazon.com/Logitech-Harm...nfrared+remote