I have both the Galazy and DM of Thoth.... honestly... the DM is fine. Assuming you have full thoth, there is not much difference in the MS, you wont see a difference... never buy a lvl 45 galazy staff as its retarded in how much they cost (1m ~ 1.2m). If you really really want one, they you can trade a lvl 45 thoth staff for a lvl 43 galaxy but honestly, no difference.

AO3 is coming out so save your bullets and better staffs will come out.