re: Is pretty much all furniture just straight up overpriced junk nowadays?

Always look under the cushions. The more springs the better, regardless of what type of spring. But in my opinion, even better than springs, are the straps made of the same material they make seatbelts out of.

Always flip the furniture over and check the wood. If it's plywood, NEVER buy it if it's less than 9 layers. 13 layers is preferable. Again... NEVER buy it if its less than 9 layer plywood. I've seen furniture that looked like it was built with plywood from lowes.

Also, avoid wood that's screwed together, other than places where screws are the only option (such as attaching it to metal). You want the wood jointed together in as many places as possible.