Plan fee as a share of $1,000 usage: Pro 4%, Startup 12%, Scale 40%

Because Sume bills generation at published model rates on top of the plan fee, the fee is a fixed overhead. At $1,000 of monthly usage it is 4% for Pro, 12% for Startup and 40% for Scale.

Fee share at four usage levels

The table shows overhead at four spend levels. Fees are monthly: $40, $120 and $400.

Why Scale is not a discount

Usage is the only variable here. Slots do not change the per-second price. They change how many jobs run at once and how long the rest wait in the queue, so a higher plan is a throughput purchase.

Worked example and checks

The shares fall quickly with volume. At $4,000 of usage the Scale fee is 10% and the Pro fee 1%. That is why the plan question is really a throughput question: once spend is high, the fee barely moves the total cost, and what matters is whether jobs finish in time.

If your spend is under $250 a month, the fee is the largest line on Pro: $40 is 16% of $250. In that range the fee is a reason to batch work into fewer months rather than spreading small spends across a year.

How to decide

Pick the cheapest plan whose slot count finishes your batch in the time you have. Do the queue arithmetic first: jobs divided by slots times average job length. Sume bills model and tool usage at the published rate on top of the plan fee, so the plan price is separate from every number in this post.