>>11999676
I use software called Junglescout, but it's not cheap. You will get an idea based on where the product shows up when you search popular search terms. The frequency and recency of reviews is also a good tell. Rule of thumb is 50 sales per review, to give you an idea, but that's very vague. if it's visible, it sells.
From what I've gathered, you're looking to sell a brand that has some traction already established. Know that if you go SFP or FBA, your margins will shrink, but you'll always win buybox over an FBM seller. If there's margin and 4-5 people in the buybox even if FBA, don't undercut, just match them. Some sellers automate their pricing and it'll be a race to the bottom. However, if you're babysitting the listing, you can try toggling your price to undercut them before switching it back for normal business hours. It is very uncommon for a large seller with a lot of SkUs to check on listings. That being said, be on the look out for automated pricing.
This next part is critical though: if you're reported as selling fraudulent goods you MUST be able to produce an invoice from the brand owner/ manufacturer. You are guilty until proven innocent if reported. Be sure your invoice is directly from the rights owner.
Also if you're introducing a new product to a new marketplace and creating the listing, it's important to research it first. What works in one country isn't going to necessarily work in another. That being said, you can choose your margin from the get go. A small PPC campaign to get the juice flowing never hurts. I'd be happy to provide more information if I knew more about what you're going for, but for your own sake, I'd recommend witholding the ASIN & marketplace from this site.