Maybe the bigger question is to either list them individually or as a set. It's seems natural to sell them as a set, because where else is anyone going to find all new OEM plastics. Maybe the tires would be better sold separately.
Those parts are in a completely different league. There's nothing to compare them to because items like that don't come up for sale often enough to be a market indicator.
Set the starting price high enough to scare off any window lickers, or a reserve you're comfortable with. Maybe a $3,000 starting price is about right, or put it at $2,999 for that 'deal' type marketing. I feel like that's low, but should get the ball rolling. Like I said, there's just not enough of these up for sale in the public, so it's hard to know until an auction is over and someone takes them home.
I doubt they'll ever be used except as a hedge against inflation.
The story of three wheels and a man...