Hmm, if you can find 10 people willing to put up $1000 / £500, then I think you will be able to make an order for 100 MiniMigs, fully assembled with parts, with a per-board cost of around $100.
If each board after that was sold for $150, including delivery and packaging and an SD card with a default environment (BTTR games, etc), then you could see a 20-30% return on the investment - which is fair enough for the people risking the money.
I don't see a single person risking $10k of their money. I also think that selling 100 MiniMigs isn't an impossible task. Turn it into a niche demo machine (writing demos in verilog + 68k) and you could shift a thousand into the scene, but that's a bigger risk.
Legally the MiniMig should be fine, hardware wise (even with the Amiga custom chip reimplementation), but getting AROS for MiniMig is quite important in my opinion for those people who want to use it as a computer. AInc will never license AmigaOS for MiniMig, and will most likely prevent Cloanto from offering it as well.