Predictable price.
Or open meter.

Fixed-price means the total cost, deliverable, and timeline are agreed in writing before work starts — the seller assumes timeline risk. Hourly (also called Time-and-Materials, or T&M) means the buyer pays per hour worked with no fixed total — the buyer assumes budget and timeline risk. The two models produce different incentives: fixed-price rewards fast clean delivery, hourly rewards billable hours.

Not always. Fixed-price contracts include a risk premium (usually 20–40%) because the seller absorbs timeline overruns. However, fixed-price wins on total cost when scope is reasonably well-defined, because hourly engagements routinely exceed estimates by 50–200% due to scope creep, communication overhead, and vendor incentive misalignment.

Hourly billing transfers timeline risk from the agency to the client, and the agency's revenue scales with hours worked rather than value delivered. This creates a structural incentive to extend projects rather than complete them quickly. It also reduces the agency's discovery cost — they don't need to understand scope to start invoicing.

Hourly is the right model only when the work is genuinely exploratory — true R&D, prototyping unknown technologies, or open-ended consulting where the deliverable cannot be defined in advance. For SaaS MVPs, AI integrations, full-stack builds, or marketing sites, fixed-price wins on every metric except vendor preference.

Every Amatrix Studio sprint has a confirmed scope, timeline, and price in writing before the client pays. There are eleven sprint tiers — seven SaaS, four AI — ranging from $1,495 (one production-ready screen in one week) to $99,995 (full SaaS in 12–16 weeks). One round of revisions is included; out-of-scope changes use written change orders. The buyer always knows the total cost.

On a true fixed-price engagement, the seller absorbs the overrun — that's the entire point of the model. At Amatrix Studio, the sprint tier list is calibrated against the studio's actual delivery data, so overruns are rare. When they happen, the client still pays the agreed fixed price; the studio eats the difference.

Yes, and many founders do. The transition typically requires a one-week scoping sprint to convert the open-ended work into defined deliverables. After scoping, the remaining work moves to fixed-price tiers. This is one of the most common entry points to Amatrix Studio — founders escaping a runaway hourly engagement.