Here's why you generally can't acquire that information:
1. The Seller and their agent don't want to disclose how much they settled for before the deal closes. Otherwise, if the deal falls apart, they don't have a chance to get more than that amount, and may have to settle for even less.
2. The Buyer and their agent don't want to tell you, because you could go behind them and offer more, making their negotiations for repairs and other things harder or impossible.
After the deal closes,then you may be able to find out the sale price, but hardly ever before.