I build these workflows rather than price them, so this is just one small run. Last week I tracked every job in a 6-job pipeline. The price list was wrong on every endpoint I checked, and always in the same direction. One page said $0.34 a second and charged me $0.374. Another said $0.08 and charged $0.15, nearly double. So if your cost model starts from the vendor's price list, it starts from a wrong number. The fix was simple. Ignore your account balance, it tells you nothing, especially on a shared account. Most of these APIs give you the real cost of the job in the response when you submit it. Save that number next to the job ID. That was the only figure that ever added up. One more thing worth knowing. You're charged when you submit, not when the job finishes. Cancel a job or retry one that timed out, and you've paid for both. No idea on sample size, 6 jobs is far too few. For scale, I expected $7.92 and was billed $8.71.