The billing unit is the IP, not the gigabyte
Static ISP proxies are pay-per-IP with unlimited bandwidth. The assigned IP is the billing unit. Traffic through that IP is not a separate per-GB line item. At the entry tier (5–24 IPs) the rate is $2.00/IP/month, stepping down to $1.30 at 200+.
Volume Residential at $0.89/GB and Premium Residential at $5.00/GB work differently. The meter follows every redirect, failed document load, and retry — not just the payload the parser kept (RFC 9110 defines what constitutes a response, including redirects most billing meters count as transfer). That gap between what your application records and what the proxy provider sees shows up clearly on browser-based work, where the same source address returns repeatedly and loads assets the scraper discards.
Here is a sanitized HAR summary from a small dashboard run using Playwright's HTTP proxy routing. The host is removed because the target is not the point.
tool: playwright chromium
route: static isp
price: $2.00/IP/month
app export: 420 MB saved
proxy export: 2.84 GB metered
main payload kept by parser: 418 MB
redirects and challenge pages: 318 MB
failed document loads: 609 MB
browser assets: 1.13 GB
retry bodies dropped by app: 402 MB
same transfer on Volume Residential: about $2.53
same transfer on Premium Residential: about $14.20
static ISP bandwidth line: $0.00The per-GB columns reflect 2.84 GB × $0.89 and 2.84 GB × $5.00. On a per-GB plan, the 402 MB of dropped retry bodies and the 1.13 GB of browser assets cost real money even though none of it landed in storage.
Watch provider bytes even on unlimited jobs
The log row worth keeping before changing plans: route name, target URL, status code, provider-metered bytes, rows saved, and the exact proxy line used. Without it, every later pricing argument is a guess.
If transfer climbs from 3 GB to 18 GB on the same job, something changed. Page weight, retry rules, login prompts, connection reuse, or a target becoming less tolerant. Static ISP pricing prevents a surprise invoice from that shift, but it does not make the run healthy. Runaway traffic can still indicate broken retry logic, mis-configured resource blocking, or session management problems worth fixing.
Unlimited bandwidth does not mean unlimited everything else
The IP sits behind real network capacity. Sites challenge patterns they do not recognize. Fair-use terms, request rate, target response policy, and concurrent connection limits still determine whether a stable source address survives the workflow month over month.
Billing model and route quality are separate problems. A cheaper pool wastes time if the route does not fit the target. A premium network can still be wrong for a category it does not allow. Static ISP fixes the bandwidth meter; it does not change what the target does with repeated requests from one address.
When per-GB billing is still the cleaner choice
For sporadic, low-volume checks, per-GB billing can cost less than holding a dedicated IP all month. Static ISP makes more sense when the IP needs to stay consistent: saved sessions, allowlists, account dashboards, recurring browser checks, and any workflow where the same exit address is part of the expected access pattern. Count the stable lines you need, not the traffic each one generates.