Are you saying you paid $18,000 for fiber optic installation at your house?
Also, do you have any problems with the connectivity or damages? If it is damaged, can you fix it yourself?
There is basically no reason whatsoever to stick with cat6 or cat7 at such lengths. Fiber beats copper in weight, speed, and reliability.
The whole project was worth it. This allowed me to install video intercoms at two gates, and many security cameras, which is what buyers want at such a property (it's a multi-million dollar estate, and I might want to sell it next year).
If the line were to be damaged somehow, I would need to call my contractors to splice and repair it. But I don't expect it to happen. In fact the line shouldn't need any maintenance over the next 20+ years. Heavy-duty conduit. Heavy-duty weather-proof enclosures for the patch panels. Etc. It's all the same stuff built by the same contractors who build fiber infra for ISPs.
That's over $11 per feet. That sounds about right. I paid $18 per feet to have a private fiber optic line of 1000 feet installed at one of my houses (in the US), going down a very long driveway, with 3 patch panels, 2 at each end and one in the middle at a gate. That was just for my LAN, not internet access. I needed the link to hook up intercoms and security cameras. I absolutely wanted 100% reliability of the network link, so wireless solutions wouldn't have been adequate. The previous homeowner had buried a cat5e line in the first 500 feet, with a cat5e repeater (underground), but its electronics failed after a couple years and its exact location couldn't be found. And he had not even put the cable in conduit.