90-95 %, and the percentage is less in hot markets - during the height of the boom, stats in FL and other states were that 60% came in under SC price. The values would be better if there were true appraiser independence, but Fannie does not REALLY want that, which might mean RR ordering, such as VA has or the former FHA panel had.
It is not a "waste of money," because for the 5-10%., it saves them from over paying or per the financing clause clause can withdraw from the deal with no penalty. That is a lot of people and for th emarekt, a lot of loans - and allowing all properties to have a WAIVER or desktop can see close to 100% close which can skew markets - a few sales a month at higher prices forms the next set of comps for an AVM or appraisal -% is