WinUAE on a standard x86 PC. Hero. And - by the way - irrelevant and off topic.
On topic: I really would welcome a Mini-Mig on steroids - it doesn't have to be the "wonder machine" that was PR'd by some of the team members.
I agree WinUAE is just an application, an incredible one, but not a physical product like Natami or Minimig so comparison is unfair.
There is nothing wrong with Natami except the price IMO. However you would need to invest something like $1,000,000 to do an FPGA Amiga from scratch to full mass production run as a product to get it well below the magic $100 price barrier. However would you quickly sell 50,000-100,000 units even then to recoup your initial investment from your first batch?
Maybe you might sell more if the machine could connect to something like Apple App store/XBLA/PSN Network style service to buy legally authorised copies of games to use on said machine for a similar price to MP3s on iTunes?
Cost of investment vs potential maximum sales is the issue.