~ So what is there to store greater values of bitcoin in a vault storage and also store in a cold wallet at the same time?
the difference is that storing your bitcoin with them, means relying on a third party. and if i am not mistaken their vault is in a way that you do NOT control the private keys. they know how much you own and you have to go through them to get your bitcoins.
a cold storage on your own means simply storing something like this:
VTJGc2RHVmtYMS9YbmZvWWswV3RXc25ZK0dyVWxMNnREQk9RaXJOa1Naai83TERvMndKbjQ1alYvSzhXSnNwagptYndUbHc5Q3lERk9ac0dOdXI5bHE1TGFOS0QwR3JvZTNhTVhxeTNyekxwSWwrOUJJenlROHc9PQ==
which for all you know can contain millions of dollar worth of bitcoin in it.
* that is an Electrum seed phrase encrypted with AES-256 CBC with no padding using "b4746d5e8a4c2ccd1f3f2c594fa0c10c" as password.
#enjoy