Appraisers are hired by lenders, you have no say on who the appraiser would be for the valuation of the home. You can go ahead and hire an appraiser but the lender will not care unless that appraiser is approved by the lender. This is no different then any of the fraud cases that have been the topics of many posts.
Generally lenders will not even underwrite the loan if you receive more then 3% of the sales price as a credit back.
Alternatives –
If the home is going to foreclosure then let it go. Attend the auction and put in a bid.
