Long Extension TV Mounts

Does anyone have any experience with any long arm full motion mounts?

I am looking for a long extension (38" to 46") wall mount for my 55" Samsung TV, I have sitting unused in my basement. It needs to have a long extension since it would be mounted in a corner and has to reach around the corner edge. Something under $300? I have found some for between $400 and $800.

Since I am an engineer, I can speculate as well as anyone and a 30"-36" extension just isn't quite long enough. So I would really like to hear only from people who have real world experience with these long extension arms and what to look for and what to stay away from and which brands are generally good. Does Costco or Best Buy sell anything worthwhile, etc.

Thanks in advance....Gary

You're going to want something with a cast arm and cast wall mounting plate, they are more heavy duty than your typical stamped mounts and support the weight of a larger TV much easier. The cheaper stamped mounts tend to sag a little and that's not what you want. Those types typically cost ~$150 or so while the cheaper stamped mounts tend to run from $50 on up.