I had not taken that into account. That does make a difference

Absolutely! Not saying you can't. I'm a firm supporter of resourceful cooking and using as much of the animal as possible. Still for pork $2 a pound isn't unexpected with a less desirable cut like shank. Frankly it still feels high to me. Just a few years ago pork butt was $1 and some change per pound. I can still get pork butt for $1.99-2.60 per pound today and I consider that a much more commercially desirable cut than shank.

It's the shank end. That's some tough meat

Ocean sand naturally has microscopic small particles of shells/coral etc. which actually make up a great deal of it. These are an absolutely necessary component of concrete. That's why glass bottles ground into sand, granite sand, and desert sand are completely unsuitable in making concrete. I believe it's more about chemical makeup than grit size (which would be completely controllable when grinding glass and stone into sand).