One 4:5 poster, four Sume image models: what a round costs

One 4:5 image from each of Flux 2 Pro, Seedream 5 Lite, Qwen Image and Recraft V4 costs $0.0375 + $0.04375 + $0.025 + $0.05 = $0.15625 on Sume. A four-model comparison round is therefore about sixteen cents. All four list 4:5 in their catalog aspect ratios, so the same prompt and ratio go to each without conversion.

The arithmetic

Each price is the provider list rate times 1.25, per the Image API docs, and you pay cost_usd x n. The list rates are in the repo's pricing table.

Note the difference between the headline and the sum: add the four lines exactly rather than rounding each to cents.

The catches

Recraft V4 is text-to-image only and returns WebP, so a PNG pipeline needs a conversion step. Qwen Image is the cheapest, which makes it a fair baseline. The cost of four prompts across four rows is 4 x $0.15625 = $0.625.

Do not read price as quality. Sume publishes no ranking of these rows, and we make no claim about which will suit your prompt. The round exists so you can judge by eye.

Run the round

The loop below sends one prompt to all four rows with the same 4:5 ratio and prints each URL. It stops at the first error.

import os, requests

H = {"Authorization": f"Bearer {os.environ['SUME_API_KEY']}"}
MODELS = ["qwen/qwen-image", "black-forest-labs/flux.2-pro",
          "bytedance-seed/seedream-5-lite", "recraft/recraft-v4"]
for m in MODELS:
    r = requests.post("https://api.sume.com/v1/images", headers=H, timeout=120,
        json={"model": m, "prompt": "poster for a night market",
              "aspect_ratio": "4:5"})
    r.raise_for_status()
    print(m, r.status_code, r.json().get("data", [{}])[0].get("url"))

Scaling the round

The same round at other volumes is simple multiplication, because each row is a flat price per image. Ten prompts through four models cost 10 x $0.15625 = $1.5625. Adding a fifth row such as Flux 2 Flex at $0.0625 brings one round to $0.21875.

If you only need to cut the field, run the cheap rows first. Qwen Image and Flux 2 Pro together cost $0.0625 per prompt, and you can add Seedream 5 Lite and Recraft V4 only for the prompts where neither convinces you.

• Qwen Image: $0.025
• Flux 2 Pro: $0.0375
• Seedream 5 Lite: $0.04375
• Recraft V4: $0.05

Before you start

Confirm the prices on the endpoint record before you spend anything, even a few cents. Read GET /v1/images/models/{model_id}/endpoints for each row, because list rates move and the catalog is the source of truth for what your wallet is charged. Keep the four generated files side by side, name them after the model id, and note the prompt, so the comparison can be repeated later when a row changes.