According to the ACube webstore, the Sam460cr mainboard starts at US$525 and full systems at US$839 (may be incl. VAT).
> and gets smoked by a $25 Raspberry Pi
No, it doesn't. You'd need at least a US$35 Raspberry Pi 2 for smoking the Sam460, and even then the Sam460 would win in most single-threaded tasks. To safely smoke the Sam460 also in single-threaded tasks, a US$35 Raspberry Pi 3 is required.
> or any supported ancient Power Mac
Not taking 3rd party accelerators into account, it would have to be at least a QuickSilver model.
