You're making unproven assumptions as well.
Not really. Your very own table provides a lot of insight. I mean, I think you get the idea. If 14% had been transferred the first year in 2010 then the calc can be carried out each year through the date where the entire ownership in the condo had been gifted to the son.
It has to be kept in mind that each year the parents own incrementally less in terms of percentage of ownership after the gifting. So the FMV may increase over the years but their percentage of ownership is decreasing. I think you get the point. That second year in 2011 for example they would own 14% less than the year before but would still be gifting $26k and what would the FMV have been in 2011?
What they should do is create a table such as the one you posted to determine when full ownership passed to the son. They're going to need the FMV for each year but that shouldn't be too hard to determine.
