Suprised to see folk saying its a bug, it isnt, its simply a default price they game system puts of items when first dropped onto vendors.
The system has a set price (extremely low) for every item ingame. It is up to the owner to ensure they enter the correct price.
Things do go wrong-
1

You drop an item, and miss price it, or add the description mid way or at the start- 4 rolls 200gp.
2

You drop an item on top of another, the new item rubber bands, and doesnt request a price...it then defaults to set price.
3

Simple things like the 'No Insured' fix can cause problems.
4

You chat on icq and forget....
Personally, if I find an error, I try to locate the vendor and will pay him 1/2 the going price, scant reward, but.....
If I cant locate, ah well, bargain, and with 3 x 50 vendor malls, I make ricks every day, and noone runs up to me handing me my error, unless they are close freinds...
Ive sold Mace and Shield for 900gp, HOM for 12gp....so yup, been there.
The lesson is, the 60 sec cool down is there to help us not hinder, if your placing a 12m item, check it......