If I buy an item, how to save the items in Vault.
My english so bad.Because I am Hong Kong people.

HELP!!
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Buy Permanent Weapon Menu:
1. 1xxxx
100 points
2. 2xxxx
130 points
3. 3xxxx
120 points
4. 4xxxx
110 points
9. Next
0. Close
Choose Permanent Weapon:
1. 1xxxx
2. 2xxxx
3. 3xxxx
4. 4xxxx
9. Next
0. Close
If you no buy 1xxxx,you can't choose 1xxxx.
If you buy 1xxxx,you can forever choose 1xxxx and save 1xxxx in Vault.
How to make this?