Sigil of Remote Storage

High alchemy turns Sigil of Remote Storage into 18,000 gp. Buying one at 200,000 gp (its guide price, as it has not traded today) and casting with a nature rune at 138 gp costs 200,138 gp. That is a loss of 182,138 gp per cast at its guide price, so it is not worth alching for profit right now.