Way to bump a year old thread, two posts up. Good job.
To actually make this worth reading, I'll share my experiences with multiple current proxy subscriptions I have.
First off, if you're using shared proxies, you're probably going to get a shit ton of 407 and 403 responses. People are assholes and it just takes one retard running 70 proxies and 300 connections with no random wait period to get an entire block marked by google as abusive.
Shared:
Proxybonanza (x2) - $17 and $22/month, respectively. ~75 proxies each subscription, 10GB bandwidth per sub, but I can't sniff that as they're constantly getting blocked by google by assholes as described above.
Proxy51.com - $35/month, I think it's 100 shared. They go up and down depending on current level of abuse, I feel lucky if I can get 20 of them to show up as google anonymous. Tons of 407 responses in scrapebox and other tools.
Private:
Buy-Proxies.org - I think it's $75 for 40 private proxies. I only use them for posting but when I do run them through scrapebox to check for google anon, it's about 30-32 proxies pass both tests. I'm assuming this is because they're overselling their blocks and google is flagging blocks used to quickly for too long of a period by google.
ProxyHub.org - $80 for 40 private, I think. Pretty much the same situation as Buy-Proxies.org. In fact, I think they're the same company selling their shit under two different names, but I haven't dug in deeper. My IP blocks from both companies don't overlap, so it seems to work.
Haven't tested squid but ultimately, your proxy experience is going to depend on who else is using related blocks/IPs and how they're using it. If people would wrap their heads around quality quantity over just quantity, we could all continue to have nice things. I try to keep my proxy:connection ratio at 12-25:1 and I can acquire targets faster than I can bot their submission (inb4 mattseh).
If anybody has a proxy service that will consistently not get blocked as bot traffic by google, feel free to hit me up.
/rant