640 Nano Banana 2.1 images at 2K: Google $16.13 batch, Sume $96.00

640 Nano Banana 2.1 images at 2K cost $16.128 on Google's Batch tier, $32.256 on Google's Standard tier and $96.00 on Sume. Google's figures are 640 x $0.0252 and 640 x $0.0504 from the Gemini API pricing page (read 2026-10-09). Sume's is 640 x $0.15 from the Sume price list. If one model and a bulk price are all you need, Google direct is the cheaper route; Sume's value is one wallet, one API and many other models.

Sume's Image API docs describe sync, async, subscribe and webhook modes, and they state that sync waits at most 30 seconds. They do not describe a batch discount, so async mode on Sume changes how you receive results, not what you pay.

The three bills side by side

Google bills 2K output at 1,680 tokens. At the Standard rate of $30 per million tokens that is $0.0504 per image, and Batch is $15 per million, which is $0.0252.

When the cheaper route is not the right one

Google's Batch tier is designed for jobs that can wait, and you handle submission and retrieval yourself. If the 640 images are one step in a longer pipeline, for example generating stills, cutting out subjects, upscaling and animating them, the Sume total includes a single balance, a shared job format and result URLs hosted by Sume.

A few numbers help you decide. Each additional $0.0252 per image Google saves on a batch of 640 is $16.13, which is small next to engineering time if you would otherwise integrate four providers. But at 64,000 images the same gap is $9,600 and a direct contract is worth negotiating.

• Under about 1,000 images a month: the gap is under $150, and one wallet usually wins on simplicity
• Over 50,000 images a month: price the direct route seriously
• Mixed image, video and audio work: compare the whole pipeline, not one image row

How to check your own bill

Run five images at 2K on Sume and read usage.cost in each response, which is the USD amount billed to your wallet. Multiply by your batch size and compare with Google's published per-image figures. Sume's catalog formula rounds a billed amount up to the cent, so for tiny batches the rounding is visible.

Scaling the same comparison

The comparison is linear, so you can scale it without a new table. Per 100 images at 2K, Google Batch is $2.52, Google Standard is $5.04 and Sume is $15.00. Per 1,000 images those are $25.20, $50.40 and $150.00. Sume's rate is exactly 2.976 times Google Standard at this tier ($0.15 / $0.0504), and 5.952 times Google Batch.

If those multiples are acceptable for a small campaign, the extra cost buys you an API that is already wired for the other steps. If they are not, run the bulk image step directly with Google and use Sume only for the models and utilities you cannot get elsewhere. Either way, keep the exact prompt, the tier and the count in your job metadata so the cost per approved image is easy to compute later.