Actually, one of the earliest Class D GaN amps is the Orchard Mono blocks.....been out for a couple of years.......$1500 the pair. They have a new stereo amp with even more power for $2500. Also made in the USA.
https://orchardaudio.com/shop/ols/products/bsc-mplfr
https://orchardaudio.com/shop/ols/products/strkrmsn-str-ltr
https://orchardaudio.com/shop/ols/products/bsc-mplfr
https://orchardaudio.com/shop/ols/products/strkrmsn-str-ltr