I have 4 of these mounts, 3 are in boxes. Price is 25 each, or whatever you think is fair for the lot.
These are pro-grade and not like the junk on Amazon. Definitely worth it if you want a swivel TV mount. It's designed for masonry walls, but you could probably reinforce your existing wall a bit and make it work perfectly in your home.
I have no idea if I have the screws and bolts, but a trip to Ottawa Fastener Supply will solve that.
Legal: Sold as-is, where-is, untested, no warranty.