I dont have a store nearby, so i do most of my headphone exploring by buying and reselling used headphones. Havent made a profit nor a loss in 20 or so headphones. But in my country (Netherlands) the market is pretty bad, especially with the higher end stuff. People try to sell their (ab)used stuff often for more than new price and get annoyed when you offer them a more realistic price.
There’s a handful of hifi shops in Seattle, but they don’t tend to carry headphones/iems. The two that do, have a remarkably small selection that varies wildly. They all cater to people looking to spend waaay too much money on full home theater setups. So the prices are all remarkably high, even for used gear. If you want $6k and up speaker cables, they’ve got you covered. I had to travel to a headphone convention to test stuff out. I’ve bought some used stuff on ebay for a good price, but it was all from out of state. Same with stuff I’ve bought online. I’d love to be able to walk into a store and get decent headphones, but it’s just not an option here. There aren’t really any dedicated electronics stores in the area.