Dang, I just ordered a new set of 31s. $1700 US each. Should be able to come up with a price for yours based on that.
I have 26 GYs, 31s, and 8.50s. My $0.02:
The 8.50s will take you anywhere you’d likely consider an airstrip even with minimal maintenance. A lot of bang for the buck. Stand up well to asphalt and a bit of tread for rainy days.
26” GYs aren’t that much better than 8.50s, in my opinion. You get a bit more prop clearance if that’s needed, but they are hard. Nothing like ABWs. I suspect they wear well, but for me I don’t really see the point.
31s (and probably 29s as well) are a whole different game. The size is only half the story. It’s the pillowy soft ability to soak up lumps and bumps for truly off airport operation that sets them apart. If you don’t plan to go off airport there’s no point in the extra weight and drag, but if you do it’s a game changer.
Maybe I should have talked up the 26s a bit more and traded you for your 31s
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