And, some BODs are rare values compared to the others.
The 20 EX cloth 5-part large is easy to fill by a skilled tailor, and gives a clothing bless deed (which works on hats, sashes, robes, cloaks, footware, etc.) People will pay far more than they'll ever save insurance from it, because of the convenience. It takes 200 normal leather and 800 cloth.
The 20 part normal 6-part LBODs in normal leather also give this, but are difficult to bribe up (tend to increase normal to Ex or from normal leather to spined). But, if you assemble a set of the parts from collecting BODs, saving for the large to show up, you can fill them at zero leather cost, by buying the items to fit the smalls.
The 20 part Ex 5-part LBODs in normal leather require crafting, and will have lots of failures (even with max talismans) - but are good for training up sub-120 tailors from where gains from oil cloths or cloth ninja hoods stop.
The 20 EX 2-part "Polearm" LBOD is actually one of the more efficient LBODs, needing only 720 Iron Ingots to fill, with the reward at the POF point value level. That it only consists of 2 smalls and a large also means that it's relatively cheap and easy to bribe up the components as well.
Almost as good are the 5-part weapon LBODs, as you can get POF-level points from any of them (and before the change to point values, you had a 20% chance of POF from a 20 Normal LBOD, but now that BOD is just below the POF threshhold).
The 6-part Exceptional weapons LBODs also can be used for POF or DC hammers.