My first speeding ticket?

I live in Portland, Oregon and was recently pulled over just north of Grants P, Oregon on the I-5 for speeding. I had been coasting down a hill, and did not pay attention to how fast I was going. The cop said I was going 86 in a 65 zone! I said I was not aware of my speed, and that I normally do not speed, nor have I ever had a ticket in 9 years of driving (I am 27). He issued me a ticket for$472.00 and said I don't have to appear in court if I pay the ticket within a month. I'm confused on the ticket, as one column says I was PACED at 86 in a 65 zone. The next one however says the fine amount, and "speed in excess of 31+ mph". How does 86 correlate to 31mph over 65? I am confused if this is just categorization of the law & violations, or if this is an error on the officer's part. Should I just pay the fine and deal with a tainted record & insurance hikes, or drive 8 hrs roundtrip just to probably be named guilty and have to pay anyway? Gah, I am kicking myself for this one!!