Welcome to the forum! Do you have any requirements and how will you be using it? For example, how many seats, using it for hunting, property maintenance, general trail riding, do you need a dump bed etc? Yes, there's lots of guys that bought machines in the past couple of years that are back to "normal" life and have no time to ride so they're trying to take advantage of Yamaha's very slow delivery times and ask a fortune for a slightly used machine since it's been hard to find new inventory for the past 2 years or so. Since you said Wolverine and 4-5 years old, I will make a recommendation based solely on my own experience, DO NOT buy a used Gen 1 Wolverine 700. Some owners have had great luck and performance but it's luck of the draw. There are well documented issues with that 708 motor. The chassis is fantastic but the motors grenade when the oil pump/water pump drive gear gets loose. No warning... just BOOM! Some have had this happen at 300 miles, some at 8000 miles. They also have a Yamaha service bulletin for oil consumption that gives you a new top end. I had my top end done multiple times before 2000 miles and I gave up and got rid of it. All of my machines are babied, serviced, and maintained. I wouldn't take any 708 Yamaha for free after all the hassle I went through. Many dealers won't even take a 708 in on trade as their wholesalers won't buy them. I was lucky and found a dealer that traded mine. (It's a long story)
If you're looking at the X2/X4 series 850 Wolverines, Make sure to thoroughly inspect the intake. There's a drain plug in the bottom of the airbox that can fall off and it sucks in water/mud. Other than that, their very bulletproof machines as long as they have been properly serviced. Hope this helps.