Compare proxy plans only after you define the same authorized workload. A lower price per “GB” can be a worse purchasing choice when the unit, included traffic, expiry, retries, overage rule or invoice meter differs. This guide compares billing terms and measured usage; it does not rank providers or claim that a plan will perform well.
1. Freeze the workload before reading prices
Record permitted sources, market context, schedule, expected task count, client type, retry policy, whether requests are cold or warm, and the validator that decides whether a result is useful. An API, licensed feed or manual process that meets the decision remains a valid no-proxy option. The source-selection guide covers that earlier gate.
2. Normalize the billing vocabulary
| Field | Write down | Do not assume |
|---|---|---|
| Metered unit | GB or GiB, included quantity and meter definition. | GB and GiB are interchangeable. |
| Chargeable traffic | Whether request/response headers, body, retries and failures count. | Only useful records are billed. |
| Commitment | Minimum purchase, term, renewal, expiry and unused-credit rule. | Unused balance rolls over. |
| Overage and adjustment | Rate, cap, notification, invoice timing and dispute process. | A dashboard counter is the invoice. |
NIST distinguishes 1 GB = 109 bytes and 1 GiB = 230 bytes. Ask the supplier which unit its meter uses. A Bright Data residential pricing FAQ currently says its bandwidth includes request headers/data and response headers/data; that is one supplier’s published definition, not an industry rule or IPHTML term.
3. Build a comparable quote sheet
Use one scenario for every candidate. The baseline is 40 GB of decimal invoice-metered traffic in the same monthly period, one required market and fixed allowed task set. The 10 GB and 60 GB rows are sensitivity cases with the same boundary. All use USD with no tax, adjustment, discount or rollover assumed. Actual identical workloads can have different metered traffic under different billing boundaries. Candidate A: 50 included GB for a hypothetical $300 monthly commitment, $8/GB overage. Candidate B: 30 included GB for hypothetical $210, $12/GB overage. These invented figures are arithmetic examples, not quotes.
A at 40 GB: $300 + max(0, 40−50)×$8 = $300
B at 40 GB: $210 + max(0, 40−30)×$12 = $330At 10/40/60 GB, A costs $300/$300/$380 and B costs $210/$330/$570. The modeled crossover is 37.5 GB: below it B is lower in this example, above it A is lower. That does not make either generally cheaper: expiry, taxes, credit rules, chargeable bytes, required configuration and a different workload can reverse the decision.
4. Separate meter evidence from useful-work evidence
Use the quote sheet in two stages. Before purchase, a quote-model comparison can proceed only when the current terms and the workload’s eligibility evidence are complete; without a real meter it is MODEL_ONLY, not actual-cost evidence. After use, keep two ledgers: the supplier-meter snapshot for invoice reconciliation, and a local workload ledger for task IDs, bytes observed where available, retries, validity and deadlines. Do not force them to agree byte-for-byte; reconcile the date range, unit, route, included traffic and known differences first. Contract terms determine the invoice; a supplier meter is one input and minimums, credits or adjustments may also apply. Local evidence explains workload behavior.
| Observation | Decision |
|---|---|
| Local and supplier periods or units differ | INCOMPLETE for actual-cost evidence: normalize before invoice reconciliation. A separate quote model may remain MODEL_ONLY. |
| Retry/failure billing definition unknown | HOLD: obtain current written terms or exclude the quote. |
| Invoice meter and local ledger differ after normalization | Record the delta and ask for the meter explanation; do not invent a cause. |
| Required workload is not accepted or permitted | STOP: no price comparison cures that gap. |
A recent public r/automation question describes a cold-run traffic estimate differing from repeated use after caching. It is one user’s report, not a benchmark; it supports recording cold/warm state and measuring a representative batch rather than multiplying one run.
5. Make a purchasing decision with missing-term rules
- Advance: the workload is eligible and every current term is evidenced: currency, tax and adjustments, validity, automatic renewal, billing boundary, retry treatment, overage budget and price. The MODEL_ONLY cost estimate fits the approved budget.
- Hold: any required term or eligibility evidence is UNKNOWN; never replace it with zero.
- Reject: terms or permitted workload do not fit; do not “solve” this by using an unauthorized route.
This is distinct from technical acceptance. Use the representative trial for workload coverage, the scorecard for outcome denominators, and the capacity guide for bounded load evidence.
6. Fill the blank worksheet before contacting suppliers
Download the bilingual billing-comparison worksheet. Copy it once per candidate. It contains blank actual fields and printed hand-calculation rules; it does not fetch prices or calculate an invoice. It separates a pre-purchase MODEL_ONLY quote comparison from post-use invoice reconciliation, where COMPLETE is the threshold for actual-cost evidence. Missing required terms remain UNKNOWN/HOLD, never zero. Replace every hypothetical input with a dated, supplier-specific written term and measured workload evidence.
For an authorized workload that may need a residential route, review residential proxies and contact the team with the workload and term questions. Confirm current suitability and terms before purchase; no price, trial, usage rule or performance result is promised.
Sources checked October 21, 2026: NIST binary-unit definitions, the linked Bright Data FAQ as a supplier-specific billing example, and the public question. All plan values and calculations are hypothetical editorial examples.