appraisal mill
n. An unscrupulous company that provides misleading or erroneous appraisals, particularly for real estate.
Examples
2010
Still, some experts say the system needs an overhaul, from the "appraisal mills" and "mortgage mills" that started the frenzy to the "foreclosure mills" now in play.
—Kimberly Miller, “Halt reveals lenders', firms' dubious moves,” Palm Beach Post, October 24, 2010
2009
And as it turns out, there are plenty of legitimate concerns about the new reforms, including the establishment of Appraisal Management Companies — unregulated third-party appraisal mills.
—Joe Weisenthal, “Wait, Maybe The Realtors Aren't Wrong This Time,” The Business Insider, June 25, 2009
2006 (earliest)
It is likely that if I replied the sender would suggest I order a domain value "appraisal" from a party of his choice, maybe sedo (via an affilate link) or a appraisal mill.
—“Domain scam email,” Ambrand.com, March 14, 2006