1. All-cash buyers get a bit of a discount simply because the deal can't fall apart due to inability to get a mortgage. Less risk for the seller is worth something. I don't know that it's worth 10%, though.
2. All-cash buyers buy differently. Let's say I have $500k, and I want to pay cash. I might buy a house for $450k, if I can find one, but I'm not going to buy a house for $550k. Just no. So either the seller can come down to $500k, or I'm buying something else, because I'm not interested in taking on a mortgage in order to get that $550k house. Whereas if I'm getting a mortgage for $500k, is getting a mortgage for $550k all that different to me?
2. All-cash buyers buy differently. Let's say I have $500k, and I want to pay cash. I might buy a house for $450k, if I can find one, but I'm not going to buy a house for $550k. Just no. So either the seller can come down to $500k, or I'm buying something else, because I'm not interested in taking on a mortgage in order to get that $550k house. Whereas if I'm getting a mortgage for $500k, is getting a mortgage for $550k all that different to me?