I have used mounts like that VideoSecu mount linked above and found that with a heavy TV they are garbage. In fact, with multiple tests of multiple cheap mounts, I ended up being extremely dissatisfied with their build quality across the board. Several bend so severely that I was sure it was going to land the TV right on the floor within a week.
I ended up dumping the cash on a Chief mount. They are far over your budget, and the only mounts that I would actually consider safe for TVs which are in the 100 pound plus weight range.
I would be happy to hear you find a mount that works really well which is under $200, but I have spent a lot of time looking and no time finding one which actually delivers on their promise other than Chief.
I've stumbled on Chief products before and was quite reasonably intrigued by them. Admittedly, it was more focused on a Mount from a sloped ceiling and they were one of the few that seemed worthy of any attention.
To be fair, the VideoSecu I linked above is what I am using with a 49" Sony x900 that weighs in around 30#. Regardless, it has not shown any ill effects of holding that TV at near full extension and is still straight and true after 2 full years.
This is the specific link for the product that would hold said TV as mentioned in the OP:
All that said, I want to stress, I fully agree with what
@BMXTRIX wrote above. A prime example is my choice of K&M wall mounts for speakers. I did not trust the common market options widely available and chose something that required physically mounting an adapter plate to the Speaker Cabinet. Strangely, that is the weakest part of the mount!
With 6 each 1/4" Lags (per mount) into studs and good anchors, I could probably do Chin-Ups on the mounts alone, no speaker attached.
Considering one of these speakers is right above my head where I stand as I type... this was an important consideration to me.
