The Robe looks correctly priced. The Scabbard, however, I'm not sure how you came to the final cost.

Sequester is 7th level, requiring CL 13th. For a use activated item based on a spell with a duration in days, that means it's cost is (SL x CL x 2000)/2, which in this case equals 91,000 gp. Since it doesn't take up a slot, that doubles the cost to 182,000 gp. Restricting to just weapons that can be sheathed and only while attended and sheathed, which I think would halve it again at best, which is back to 91,000 gp.