B6 Aizen and weapon dupes

So just got B6 Aizen today (from B4, B5 dropped at fourth pull, B6 at flippin' first!).

Are weapon dupes worth it/ must have? If yes, how many of them?

More context: low spender, currently 28k jades, skipping Nel (don't care for Gin) and will yet see about Mayuri.

Thnx in advance.