A proxy gives you an exit address and nothing else. A scraping API takes a URL and returns the page, handling address choice, retries and often rendering. The question is who carries the engineering and the retry cost.
What a proxy leaves to you
- Choosing rotation and session behaviour per workload.
- Retries, backoff and detection of soft blocks.
- Rendering, if the page needs JavaScript, and the bandwidth that costs on per-GB plans.
- Monitoring success per target over time.
What an API takes over
Billing is per successful request, so retries stay on the provider side of the meter and a crawl budget is a known number. In exchange you accept less control over each request, and a per-request price that has to be compared with proxy traffic cost.
Choosing
- Easy targets at high volume: proxies are usually cheaper, and the tuning is small.
- Hard targets that change their defences: an API or unblocker moves that tuning to the provider.
- Small team, many different sites: an API saves engineering time you would spend on per-site fixes.
- Either way, measure cost per success on your own targets with the same definition of success.