Credit cloning

The strategy is simple.

• Move all objects in the shop to a single pile. Drop a cursed item to prevent your pet from moving on to it.
• Drop gold into the shop. The shopkeeper will give you credit for the gold.
• Let you pet steal it for you.
• Go to the pile and buy as much as you can from your credit.
• Sell all the recently bought items, even items that you own.
• You may need to buy and sell several times before you can exhaust your credit if you had a lot of starting credit.
• Drop the old + new gold in the shop and repeat from letting your pet steal it.

Repeat the technique till the shopkeeper has no gold (when it starts to give you credit when you try to sell the item). And you have enough credit to buy everything that you want from the shop.

The technique is very time consuming and must not be done if you don't have enough food.