As said, the cheapest is not always the best. I built an SMM business selling services for far more expensive than most places, but it depends on the clientele you want to serve. Give good customer service and you are better than 99% of panels and will retain clients even if the services you sell aren't as cheap as physically possible. Cheap services are often unreliable at times and can cost you loyal customers, better to prioritize finding quality.
As someone who was in a very similar mindset to you when beginning my SMM journey, it is a waste of time trying to find "The main provider" There are lots of different panels specialising in certain social media, search service names, or descriptions as often most panels are too lazy to change them. I know an owner of a very similar panel in size/market to JAP and they have written contracts with a provider to provide services exclusively to them, as they have such a huge share of the market.
Customer service is very important and I have spent $200,000+ on certain panels and still get the same half-assed customer service even from the owners. If their service had been better, this number would have been much higher, but I opt to give business to other providers, even if the cost is slightly higher to get more responsive service.
Good luck on your journey and as mentioned, you can search all of the domains registered to the same IP as Perfectpanel to find the majority of panels that exist. There is a thread on BHW with the list if you do a bit of digging.
