insurance rates seem to wander around anyway .... .I've been paying a bit over $100 a year for my motorcycle, then I got a renewal, and they wanted something like $300 a year, I was like, WTF? I checked other services and in person, face to face in an office, it would be $175 a year, a bit better. On-line, they wanted from $1700 to $2500 a year, typical Internet exorbitant pricing, and I'm sure some saps pay this too, I know, I used to sell stuff to morons online!
I finally got to talk to the alpha male at my insurance office (first time I saw him, I'd thought this other kinda dumb peon was the alpha male) and he fixed everything, and my insurance went down to below $100 a year. Turns out there were discounts I got that had expired, and they'd happily charge me more if I didn't complain - woops, I complained.
I'd consider a $3 change to be basically meaningless. The whole insurance racket reminds me of this pizza place I used to buy slices at, the price was always different! It was always $3 and some, about $3.25 to $3.50, it was really strange but it always was a different amount. I tried talking with the people who worked in the place about it and they were not smart enough to discuss it.
Recap: With any organization, find the alpha male and deal with them. And, insurance costs can be expected to "dither" a small amount randomly, only consider it meaningful if they change a lot.