Want to create and manage 15-20 IG accounts (Using Jarv) with maybe 1-3 churn n burn accounts. Budget is low. Looking into Raspberry Pis but......

We're researching this so hard....

My budget is low we want to make about 15 to 20 IG accounts, but looking into it seeing is the only true safeway but not bulletproof is using 4G mobile proxies...

https://www.blackhatworld.com/seo/diy-how-to-create-your-own-4g-proxy.1234185/
This is best known method that I have very little capital to invest in and start to use. I'm worried if I get this that my Spectrum modem which has given me trouble before won't configure properly.

Since Instagram has tightened their grip on automation. It feel frustrating that I already lost cause it takes a lot to just get started to build 15 to 20 main accounts.

Residential proxies should still be an option for you. They're a bit cheaper than 4g proxies.