Stronghold Builders Guide page 70 says "bulky but technically removable" magic items cost half and totally immobile ones cost a fourth the normal price. The Bier of Ressurrect the following page allows unlimited Resurrection with only a 500 gp diamond each. Chamber of Speed for 15,000 halves the completion time of "most tasks" (though is dependent upon 3.0's cheesy, super broken haste).
Nice. So if you want to craft a magic item that is made for out-of-combat use (like for healing, camping or transportation), make it "bulky". Once it's used, put it back in the Bag of Holding.
What objective criteria would you use to label a magic item as bulky?