I did consider Amiron's cheaper sibling Beyerdynamic 1990 as replacement for my Audio-Technica ATH-M40. Then I was introduced to open back Planar Magnet speakers, Hifiman Edition XS for under £500.
These speakers are without doubt the best speakers in their price range. I like the transparency, extraction of detail and wide soundstage and sweet treble and full deep bass without lumpiness of the dynamic headphone alternatives.