Well you are right when you compare it directly on the other hand: a Winner 630 will fetch way more then an M-Tec 1230, an A3630 is even nearly completly worthless in compareson, though they deliver about the same power.
The accelerator is specifically made for the the phönix and was designed only a few months ago. A very limited number was made.
My forecast would be something around 400 EUR.
Got about the same setup still unassembeld, will nerver sell it ;-)