I'm not sure that's correct -- the first party APIs are priced per query but BD is per 1k results. Not immediately obvious what they count as a "result" tho.
It's really poor wording. Bright Data does indeed consider 100 results in a single request to be a single billed "result" event, billed at $1.5/1000 requests.
I always set 100 results per request from Bright Data, and I can see my bill indeed says `SERP Requests: x reqs @ 1.5 $/CPM` (where `x` is the number of requests I've made, not x * 100).
For serper.dev, they consider 10 results to be 1 "credit", and 20 to 100 results to be 2 "credits". They bill at $50/50,000 credits, so it becomes $1/1000 requests if you are okay with just 10 results per request, or $2/1000 requests if you want 100 results per request.
(Both providers here scale pricing with larger volumes, just trying to compare the easiest price point for those getting started.)
For 100 results per query, serper.dev is $2/1000 queries and Bright Data is $1.5/1000 queries.