It's $60, but consider that as a cost not for a production device, but instead as a commercial development board, letting you get hands-on experience working with each of the chips on the board before you design them into a mass-production product.
While that's true, the chips aren't themselves cheap; together they cost £6.90 (if I read the pages right) if you're buying from digikey by the 500.
The bigger concern is what you're actually doing with the crypto. Almost every use for crypto is intrinsically linked to transmitting the encrypted data; the amount of work to do something nontrivial would be pretty mental.
Any commercial project would probably approach the problem at a higher level; i.e. you'd buy an ARM microcontroller and a TLS stack.
