vendor storage should stop. Bods ought to have a default cost of like 500gp
Other than deliberately killing the BOD system, what other reason would you have for this?
The ability to store BODs in BOD Books on Vendors was ALWAYS INTENDED. Granted, the intent was to encourage BOD Trading (but, 99% of the time led to BOD Hoarding instead). That is why even PRICED BODs in the BOD books don't count toward vendor rentals, either. Technically, the BODs aren't really worth anything to the possessor - they are contracts that if filled act as "Pay the Bearer on Demand" with the issuing type of NPC.
The simple fact is that many of the people with BODs on vendors using them for storage WOULD sell many of them, if they weren't so %#$%#^#%^ tedious to price one by one.
I would, however, be in favor of not allowing filled BODs to be put into books on vendors. That's a whole other matter from this, as it's a silly way to sell hammers and runic kits without having to pay vendor fees (and as books of filled BODs played a part in the runic duping schemes of the past, I would make filled BODs not shard transferable in books, requiring they be outside books for the trip).