Traffic Advice? Speed ticket

Looking for advice on whether I should bring a traffic lawyer to a ticket negotiation in NY.

A couple of weeks ago I got a ticket for not wearing my seatbelt, which I already pled guilty to.

Then, about two weeks later, I got pulled over by a NY State Trooper on the interstate. He told me I was doing over 80 in a 65. I handed him my license and registration without any issues.

He asked if my license was clean, and I said yes. I completely forgot about the seatbelt ticket from two weeks earlier because I wasn't thinking of that as part of my driving record.

He went back to his car, came back, and gave me a ticket for "speed not reasonable or prudent," which, from what I understand, is a 3-point violation if I'm found guilty. However, he did not write the speed I was going on the ticket. 

As he was handing me the ticket, he also thanked me for wearing my seatbelt and then said something along the lines of, "Make sure you tell your friends to wear theirs too." That comment was completely unsolicited and kind of caught me off guard. I don't know if he was referencing the seatbelt ticket he had just seen when he ran my information or if it was just a generic safety comment.

My appearance next week isn't the actual trial, it's basically an opportunity to negotiate the ticket with the prosecutor.

My brother thinks I should just go by myself because these negotiations are pretty routine. A traffic lawyer I spoke with, of course, thinks I should hire him and have him come with me.

I'm trying to decide whether it's worth paying for an attorney or if this is something people typically handle on their own.

For those who have gone through this in New York:

• Is it common to negotiate these tickets yourself?
• Does having a seatbelt ticket from two weeks earlier make the speeding negotiation any more difficult?
• Is there any significance to the trooper's comment about the seatbelt, or am I reading too much into it?
• Would you hire a lawyer for a situation like this, or save the money unless negotiations fall apart?

Location: Kent, New York.

I'd appreciate any advice from people who've been through the NY traffic court process.