Polaris 570 or 325
I am running an ETX. I use it on the ice and have no real issues with it. It gets my kids and my gear on and off the ice without issue. It has EFI so cold weather starts are not an issue. With that said, buy the biggest you can comfortably afford. I was more comfortable buying a new ETX than I was a larger used machine, and that's what my budget permitted at the time. No complaints to speak of.
We looked hard on the used ATV market and couldnt find anything comparable that justifies the asking price.