You're not alone - there are a lot of properties out there whose assessed value reflects their value before the prices dropped, so ......you could only hope for a successful appeal.
In the situation you mentioned it certainly is a good idea to contest the value of a home in this market. The county sill not take into consideration what the bank foreclosure value is but what other normal homes have sold for over the last year. But you will need to be in title and ownership to appeal the valuation of a home. At closing, the title company will normally use the most recent tax valuation to calculate what you pay.
Robert McGuire ASR
Your Castle Real Estate
Direct - 303-669-1246
Call me when you're ready to protest your tax burden and I will help you prepare your case.