Just WOW… I have no idea when the prices became what they are now, but the smaller “Half Keyboard” debuted in 2001 for $99. Charging $600 for a 23-year-old keyboard design for the Half Keyboard in 2024 seems like straight out exploitation of the disabled and intended to bilk government agencies.
Matias deserves to be pilloried over this pricing. It’s gross.
For any future search/Google visitors: look for a split ortholinear keyboard that supports QMK/VIA or VIAL software. You’ll be able to customize your keyboard to do exactly what the Matias boards can do at a tiny fraction of the cost. Additionally, there are hundreds of friendly people on KeebTalk or QMK Discord groups that can help you with the customization if you run into challenges. 
Edit: other than keycap legends and some simple programming, the $150 Dvorak Pro Keyboard and the $600 Half-QWERTY Pro Keyboard appear to be identical:
