1. Select Product: Click on a product from search results to view available variants
2. Choose Variant: Select condition (NM, LP, MP, HP, DMG), language (EN, JP, etc.), and printing (Normal, Foil)
3. Set Quantity: Enter quantity using number pad or quantity buttons
4. View Stock: See real-time inventory levels for each variant before adding
5. Add to Cart: Click "Add" or press Enter to add item(s) to cart
6. Edit in Cart: Modify quantity, remove items, or adjust variants directly in cart

Variant Matching: System automatically matches products by condition, language, and printing. If exact variant doesn't exist, it uses best match or creates new stock entry. Stock items include comment and remarks fields preserved during sales.