High-rise condo depreciation: how much land value tot exclude

[Ted R.]

Great forum discussions here.... I read several relevant threads but my question focuses on how to split between land and building value in a high rise condo for depreciation purposes.

I purchased the condo 10 years ago for 250k in a commuter town in the NYC suburbs (downtown highrise building w/300 condo apartments; no real vacant land nearby for price comparison purposes). The condo includes in the deed 0.25% common interest (i.e. LAND and other common elements).
FMV in 2012 >300k, according to comps from sales. Since purchase price < FMV I will need to use the former for depreciation.

I moved out in mid 2012 and have been renting it since; now I need to calculate depreciation since the conversion to rental.

The original appraisal does not split between land and building value. The 2012 town tax assessor's values the condo at less than half FMV. The land is assessed at 22k and the building at 90k for a total of 112.

I see 3 options of splitting land vs building value:

1) assign 22k to land value (simply per tax assessment) and use 228k for depreciation. That would be about 10% value for land.

2) use the ratio between land and building from the city tax assessment and scale it to the purchase price (of 250k). i.e. land value = ~50k and depreciable building portion =~ 200k. That would give about 20% value to land.
BTW if 50k = 0.25%, the cost per acre of land would be 9 milion :)

3) Another option that I saw elsewhere is that some CPAs claim that condos in high-rises have no land value... so basically use 250k for depreciation and 0% value for land. Would that even fly in case of an audit?

x) The last option would be to get a new assessment for land vs building value but I doubt I can get that done by 4/15.

I am interested in your learned opinions :)