Adjusting the tax depreciation basis???

[Jack H.]

I purchased a property at the height of the market in 2005. We lived in the property for 5 years and started renting it in 2010. Original price was $445k but in 2010 they were going for more like $360k. My tax guy told me I had to use $360k as the basis which is what we have used for the last 10 years. This has always bothered me because I felt like we should have been able to use the acquisition price of $445k since it was our intent to eventually rent it out.

Is it reasonable to find a CPA who might be able to make the adjustment and file amended returns for the previous years? OR, is it "water under the bridge" at this point?