Usually I use free proxies.
Yesterday I needed to grab prices from big online store, the URL list was over than 2 million.
FREE proxies:
speed at the beginning öwas up to 1300 URLs \min., http request 1.2 per URL,
then speed decreased up to 260 URL/min., http request 5.3 per URL
It means -90% proxies was banned by cloudflare.
The speed of 260 URLs/min is very slowly for 2 million an URL (((
I buy PAID FAST proxies:
I used awmproxy rate for 1000 flows(threads).
Speed was 5120 url\mines !!!!, http request 1.1 per URL,
then speed decreased up to 4600 URLs/min till the end of process,
http request 1.2 per URL.
I recommend awmproxy to grab(parsing) large volumes under protection of cloudflare.