That's a 3 digit hourmeter. My YM186D only shows 36 hours!
But when I bought it I had to rebuild the worn out steering box - and discovered it had been rebuilt before. So probably over 2000 hours actual.
If you have really found an as-new YM186D it is worth whatever you have to pay for it. I think this is the best small tractor ever.
But verify the apparent condition. Ask for the original purchase paperwork and manuals, if possible. While a no-hours 30 year old tractor is possible, a misrepresentation is also possible.
Answering your questions - No issues with this model. With real high hours the normal stuff wears out same as a car - battery, belts, maybe eventually the starter, etc. This is a generally bulletproof model.
Price? maybe over $5k for the bare tractor (if its really that good), plus the value of any implements. There was a recent thread discussing the same issue, maybe the same tractor. I think that guy concluded it was really 1030 hours and well maintained.