I regularly review the furniture at an online auction for a local estate auction service.

Most of the furniture there seems to go for 10%-20% of new cost. It's rare for a piece (or set) to go above about $400. There are exceptions for very good condition antiques or pieces with collectible labels (e.g., original Stickley). Pieces in lesser condition or just not that good to begin with go for a few dollars sometimes.

It's sort of a shame. Some of it is just old furniture much of it "mid 20th century"(as you would expect from an estate. But a lot of it is very good condition and serviceable. It's also often much better constructed than stuff coming from offshore today. Even putting money into refinishing or reupholstering, as long as you like the style, I think it would be a good deal for someone.

When we auctioned off my parents' estate furniture, I found the same to be true. A few pieces got bid up, but most of it went for cheap.