Just my 2 cents.
Fence installs can be difficult. As someone above said, 60 holes are a LOT of holes. The spacing has to be correct, they need to be lined up correctly, the depth needs to be uniform, etc. If the post holes are off, the entire fence can be not straight and very crooked, both in the horizontal and vertical. If you hit rock, you need to know how to deal with it and potentially know how to pin the posts at the bottom. Be ready for much digging, mixing concrete, and tamping soil. As an FYI, most professional fence builders dig the holes by hand. Those augers look neat, but they can be dificult to use. For 60 holes, it will take at least 1 day, maybe 2, even with an auger. And that if you dont hit rock. Spacing for the gate posts can be tricky. The spacing has to be just right in order for the gate to hang correctly, and latch correctly. A fence also needs to look good. I think of it as like the trim work in your house. Nothing looks worse than crown molding joints, or casing miters that are gapped and dont fit. Same with a fence. A crooked fence, gates hanging badly, etc, make an awful look to a finished yard.
Also, almost 500 feet of fence will not go in quickly. A DYI job here with no experience will take you several days, if not a week plus to get this done. Even with an experienced crew of 3, (2 who know what they are doing and 1 grunt on a wheelbarrow) would take 3 days to do this size of job. As an aside, I kow many professional landscapers who have been in the business for 30 years who will not touch a fence of any kind. And these guys build Versa Loc walls and complicated hardscape. They sub fences out; too difficult to get right.
Believe it or not, i'm not trying to discourage you. I'm just pointing out what your getting yourself into. 3K for labor (I'm assuming your $8600 is for materials) plus the gurantee's that I assume would go with the install is not that bad. At 483 feet of fence with 3 gates, that works out to about 6 bucks a foot. Not a bad price, really, for a professional install.
