Love the idea!
Currently there is a random chance to drop the item, and you can't buy it on the store yet, but you will be able to in future versions!
I left one save item hidden in each dungeon, so players can save their game at least once per dungeon, but we are thinking on how to actually handle this. I want to have a little RNG but i don't like the idea of totally depending on random numbers to get a item that is so important, yk?
Currently my main reference is the Fear & Hunger saving mechanic, where you can find a safe spot around the game map to save your game safely, but after saving for the first time on that place, it is not 100% safe anymore, so you have to try your luck rolling a coin :D
Thank you for your feedback ❤