The point being that you have underpowered over priced hardware compared with the rest of the World and in return you choice of software is extremely limited and the OS lacks basic things like memory protection.
SO in the end you pay much more and get much less in return. On a simple dollar based performance comparison with other computers on the market (MS Windows, Mac OS, Linux,BSD, Haiku, etc) the Sam board quite frankly stinks.
Of course the Amiga market is not the general public, it's a small group of collectors, so the dollar performace ratios don't matter as much, if at all. Indeed, a high price for low performance hardware is an excellent gatekeeper to keep the hoy polloy out. Nobody is going to buy a SAM board based on a rational decision, thereby making the price the perfect way to restrict membership in the club.
It also helps to rationalise why nobody from the general public are buying them. A market priced Amiga not selling would leave only one explanation, there's no hidden millions of people out there waiting for it. That would shatter the hopes and dreams of many Amigans. Better to keep the price up and maintain the myth.