If you are doing RA, then I would not be paying for tools such as Jungle Scout or Helium 10, as this would be a waste of money. Those tools are better suited for keyword research, etc. Since you are doing RA and will be selling on existing listings that already sell, there’s no need for expensive software. Seller Amp and KEEPA are all you will need.
Been doing RA for 8 years. We have a mentorship program and a service business. When we have a new student SellerAmp is a must have tool. They will not learn our methods properly without it.