Yes, both Sellzone and Jungle Scout offer a Free Trial.
Sellzone is designed for Large Enterprises, Medium Business and Small Business.
Jungle Scout is designed for Medium Business and Small Business.
The starting price of Jungle Scout begins at $19/Month when Billed Yearly, while pricing details for Sellzone are unavailable.
Some top alternatives to Sellzone includes Serpstat, Ahrefs, SE Ranking, SEO Scout, SEOBrowse, SEO Explorer, Jungle Scout, SEOcrawl and SerpMaze.
Some top alternatives to Jungle Scout includes Sellics, AMZ.One, Marketplace Manager, AMZScout, AMZ Alert, AMZInsight, Helium 10, Optiseller, ProfitGuru and AMZRank.