A cheap AI image API can cost you more than it saves

I would not risk customer photos, image quality and delivery dates to save a few cents on an unknown AI API. For business work, I prefer the official API.

If I need a gateway, I want a provider with a reputation and a clear explanation of where requests go. “Same model, lower price” is a sales claim. The image still has to pass inspection.

An API gateway sits between you and the model provider. The offer is easy to like: the same familiar model name, a much lower cost per image. Why pay more?

Then you download the file. The face looks flat. The fabric needs another check. You generate again and wait. The API bill got smaller. Your workload did not.

This cheaper image failed the close-up check

We compared the same photos and instructions through two gateways. I am using partial names here: …Mart and …YI. Both requests selected 2K. The …Mart endpoint was sold as GPT ext; the …YI endpoint was GPT.

Left: …Mart, 461×461. Right: …YI, 538×538. Both are original-size crops, without enlargement, sharpening or retouching. The crop files are preserved unchanged on this website.

The skin on the left looks flatter, with harder edges around the eyes and eyebrows. The right has more natural skin and hair texture. A small full-body preview makes the difference easy to miss. The face makes it clear.

The complete files also had different dimensions:

The …Mart image had about 27% fewer pixels than the comparison image. Its visual quality also fell below our requirements. We excluded that GPT ext endpoint.

You do not need to find out exactly what happens inside a provider's system before rejecting an image. If you cannot use it in a product listing or send it to a customer, a low price does not fix it.

The price list leaves out your time and customer data

Cost per image is easy to compare. Time spent checking and redoing images is harder to see.

You save a few cents, then inspect the face, check the fabric, change the prompt and wait for another attempt. Count those minutes too. A successful API request is not necessarily a usable product photo.

Supply matters as well. Some unofficial APIs wrap a consumer website or subscription account. If that account is blocked or the website changes, the service has another problem to solve before your work can continue. OpenAI's consumer terms restrict account sharing, automated extraction and bypassing limits. I would not build a delivery promise around access that depends on those practices.

Then consider what you upload: an unreleased collection, a model's face, a customer's commercial files. A gateway handling those requests is another party receiving that material. Who runs it, and what happens to the files?

Researchers studying third-party AI routers observed malicious behavior in their language and coding samples. That is evidence of a risk in this market, not proof that either gateway in our image comparison leaked data. My choice is still clear: an unknown supplier is a poor place to put customer material just because it is cheap.

Know what kind of access you are buying

I would choose the official API first. If a gateway is needed, I would look for an established provider that can explain its upstream access and data handling. A label saying “official” does not settle either question.

A lower price still has to pass the quality check

Our comparison was not a rejection of every cheaper endpoint. We attempted 20 route comparisons and received both images in 19. The other tested routes produced acceptable sample quality.

A cheaper service that does the job is worth considering. A familiar model name does not guarantee the same result. We kept the acceptable results and rejected the endpoint that failed our requirements.

These images do not prove model substitution or reverse engineering. They are enough to explain why we would not use that GPT ext endpoint.

Prices and limits of the comparison

Our October 15, 2026 price snapshot recorded …Mart's default public prices in USD, without membership discounts or top-up bonuses: Nano Banana 2 cost $0.020 at 2K and $0.025 at 4K; Nano Banana Pro 4K cost $0.040. The token-billed GPT rates were $4 per million text input tokens, $6.40 per million image input tokens and $24 per million image output tokens. Our two token-billed GPT images cost $0.076026 and $0.061932.

The excluded GPT ext endpoint's listed 2K / 4K prices rose from $0.014 / $0.021 to $0.030 / $0.040 between our October 12 and October 15 snapshots. These are dated records, not a live price quote.

The inputs were AI-generated clothing and virtual-model samples. Each pair used the same source images, image order and final prompt. Twelve pairs were generated on both sides on October 12. Eight reused comparison images from September 22–23. The GPT image shown above came from …YI on September 23 and …Mart on October 12. The endpoints also accepted different quality controls. The gateway alone cannot be identified as the cause of the difference.

We generated one image per request on each route, without a fixed seed. We did not measure long-term reliability or concurrent workloads. The 27% figure compares total pixels with the other file; it does not mean 1536×2048 is “fake 2K.” The ext endpoint did not promise that exact larger size. Original files, usage records and pair details are retained internally.

Download one original and check it

Start with a product you sell often. Use the same photos and instructions for a comparison. Download the original files, check their dimensions and zoom in on faces, fabric, prints and lettering.

Count the retries, inspection time and waiting time alongside the API charge.

If the image fails, change the endpoint. A low price is a poor reason to accept a bad result.