I bought land and a house 10 years ago. Someone wants to buy most of the land, but not the house at a price rather higher than I paid for the whole property. (that probably won't surprise most of you, but around here property hasn't gone up in value for about 15 years)
How do I handle taxes on it? It is a reasonably unique property (as I found out when I tried to contest the assessment a few years ago. My lawyer contacted the best appraiser in the area who said he didn't want to take my money when he couldn't give me a meaningful appraisal.) so it is just a wild guess what the remaining property is worth. Likewise, it would just be a wild guess as to what the two parcels were worth 10 years ago.
I suppose the IRS wouldn't be in any better position.