€ 50.000,-- is quite a steal. It means you can have one person working at it for maximum 6 months. That's what he/she will cost in wages and other work-taxes. If you want something of a prototype thrown in as well, the design should be done within a month or four... by a single person!
So, that seems only doable if:
a) The person has done Amiga PPC boards in the past.
or
b) They have been working on it in their spare-time allready and are looking for a quick buck ;-).
or
c) Developing a PPC board for classic Amiga is extremely simple ;-)
Pick your option, or add to it :-D