When purchasing a property like this, you are taking on the risk, so plan on paying the tax for a while until you are able to work with the city! Don't assume anything!
Somtimes the properties you by at action are not in the same condition as the other properties in the same area. It seems tat a lot f folks take care of their property the same way theydo their bills, poorly. If you find this is the case take pictures or spend the money to get an independent appraisal on the property to show the tax office and don't do too much to bring up the value untl you complete your protest.
You can protest the taxes each year. You can also hire someone to do it for you. Tax authorities are not always willling to bring value down to sales price, especially on foreclosures or auctions, but it is worth a try. You can also go to arbitration where there is perhaps a better chance of having a reasonable person hear your case.
If you have that ability, arm yourself with good area comps, as well as current pictures and required repairs of the property - anything to justify the current value. You may not get it down to the auction sale price, but you should be able to get a significant discount.