I understand that it can be hard - as someone new to the Instagram game - to determine what is quality and what is trash, proxy wise. The route you should take depends on your end goal. If you want to grow a single account, just buy a mobile proxy. Done. If you want to grow hundreds or thousand of accounts the cost of the infrastructure plays a bigger role.
Obviously for one account its not worth making your own proxies, and even if you make your own proxy, the ASN provided by your server provider might be as flagged as the bad proxies you can buy. We are using our own proxies since Dec 2016 and even have our own mobile proxy infrastructure for clients and partners we work with. I know not everyone wants to go that route, but for us it was a good decision.
If you have more questions just tag me

. Hope I could help.