The link above will tell you what the conditions are. Just like you got to be a certain age to drive a car, you got be a certain age to have a regular, full time job during normal school hours, for example.
1 Most installation jobs will be within the $200 to $350 range. 2  For those who want to do the job on their own, a wall mounting kit will cost anywhere from $20 to $75. 3  For instance, this highly-rated Cheetah Mount retails for $25. Running audio wires can add to the cost. 2  Additional accessories, such as an HDMI cable, can cost $25 to $90. 3  If you also want to mount your DVD player and other systems, you will need a shelving bracket to be installed next to or beneath your TV.
For what it's worth, by the way, if you can mount the tv on a frame that will allow it to tilt that is very helpful. We recently purchased a 58 monster (husband's choice, not mine ;-)) and were planning to mount it flush to the wall for aesthetic reasons (less bulk and intrusion into the room).