Most estate sales are run by professional liquidation companies these days. The prices on the first day of the sale are usually not negotiable at this type of sale. Prices are usually reduced the second or third day, depending on the length of the sale, and usually in increments of 25% (although some will go half price the second day of a two-day sale).
If discount policies aren't clearly posted, don't be shy about asking one of the estate sale workers when prices will be reduced. The number of items left for discounting on the second or third day depends on how reasonable the prices were marked in the first place. If merchandise seems to be flying off the shelves on day one, don't count on the piece you have your eye on to be waiting for you once discounts kick in later. As they say, buy now or cry later.
Estate Sales Conducted by Families
Occasionally you'll run across an estate sale being conducted by a family. Although merchandise may be offered throughout the house, these sales are more like garage sales in terms of pricing and discounting. You'll usually have more leeway bargaining here, even on the first day of the sale. Make an offer just as you would at a true garage sale.
Take a look at more suggestions for haggling to get the best price in a number different selling venues commonly frequented by collectors: