520 euros? At the current exchange rate to US dollars that is actually not bad.
At least it would have a standard fpu (that Tabor won't) and it will run both MorphOS and OS4.1.
Actually, I just noticed that BOTH of those are included which goes a long way toward justifying the price.

The alternatives, a SAM460 or an X5000 would cost more (they would offer better video card support though).
And I'm not a big fan of the Pegasos' AGP slot design, its not an complete AGP implementation and the voltage supplied to the slot is too high.