Every product can carry more than one price — a monthly and an annual rate, a USD and a EUR price, a flat fee and a volume-discounted rate. One price is marked the default; the quote and invoice builders preselect it, and you can switch to any other price on a line. The pricing model below is a property of the price, not the product, so the same product can be billed several ways.

• Flat — one unit price, multiplied by quantity. The default for most catalog items (for example $250/hour or $49/seat).
• Tiered (volume) — the whole quantity is priced at the rate of the tier it lands in. Buying 120 units at the 100+ tier prices all 120 at the 100+ rate.
• Tiered (graduated) — each tier is priced separately, like tax brackets. The first 100 units at one rate, the next 100 at a lower rate, and so on.
• Package — sold in fixed bundles (a "pack of 500"). The package size sets the unit; partial packages round up to the next package.
• Rate card — a named set of rates for different roles or SKUs, useful for professional-services billing where each role has its own hourly rate.
• Percent of value — the charge is a percentage of a basis amount (for example a 3% transaction fee). You set the basis on the line.

Open a product and use the Prices section to add or edit a price. Each price picks its pricing model from the same set above, and the editor adapts to the model you choose:

• Flat — just the unit amount.
• Tiered (volume), Tiered (graduated), and Rate card — an editable band table. For volume and graduated tiers each band sets an upper quantity (leave the last band's bound blank for "and above") and its rate; rate-card bands are keyed by role instead of quantity.
• Package — a single package-size field (the pack quantity that sets the unit).
• Percent of value — a single percentage-basis field.

A product can hold several prices at once — different currencies, intervals, or models — and one is marked the default. The default is what the quote and invoice builders preselect, and you can switch a line to any of the product's other prices.

When you add a catalog product to a quote or invoice, the chosen price is snapshotted onto the line — its name, model, and amount are copied. If you later edit the catalog price, documents that already used it keep the figures they were created with. This is why a quote you sent last month still shows the price the customer agreed to, even after you raised your rates.