Once you start looking at trenching fiber you're looking at 10ks to 100ks. Not really my specialty, I would be looking at doing it wirelessly but yeah if you need 10gbps there's not a good wireless option right now. You can get up to 2gbps reliably on licensed wireless links, but in that area (lots of rain?) You'll need short links (3-4 miles tops) and big dishes.
Reminder: Check if in your city, the municipality has empty cable tunnels to each building – in many cities, that’s a thing, and you can pull your fiber through there with a simple RC car, and usually use them for free.
