For $799 just for a secure cryptophone, I would rather buy a hardware wallet and an iphone 6s.
What we need for cryptocoin security are cheaper solutions, not more expensive ones, I reckon. That's why some people still prefer paper wallets for personal, long term cold storage. It's simple and cheap.
Yes, buying a ledger nano and a top of the line smartphone would be the better option instead of paying $799 (plus shipping fee) for the Sikur phone. A steep price to pay for security that is not yet proven compared to the cheaper available options out there.