Merchant Mode Checklist:

Many people come here asking about why merchant mode isn't working for them and what they're doing wrong, so here's a little checklist of all the requirements for opening a shop.

• You must be level 10 or higher.
  
• You must be in town in a "safe zone" area. That's anywhere but the arena.
  
• You must not have any filtered words in your shop title.
  
• If you are selling a pet, it must be unequipped and its skills must be reset.
  • Take it to the Animal Trainer to have its skills reset for free.
• If you are selling equipment, it must be unequipped, unmelded, and unsealed.
  • Armor and weapons can become sealed when you die with them equipped while your name is red. Take them to the Archbishop to have them unsealed for a fee. The more they're "modified," the more he will charge you.
• If you have closed shop after someone bought from you and are trying to reopen with the same shop window, the amounts of the items sometimes double and must be re-input.
  
• If you have closed shop after someone bought from you and are trying to reopen with the same shop window, you must not have re-input anything that they bought you out of. The item will still appear in your merchant mode window inventory until you close and reopen the window, but you cannot sell it--because you don't actually have it.
  
• If you are selling a package, the "Package" checkbox must be checked and a price must be filled in.
  
• You cannot have commas in the price of anything
  
• If you are selling an Ichi or Scrachi, you must de-equip the items on the pet before you can sell it.
  

I think that's it.