Worth hiring an Amazon marketing agency to launch/manage products?

I’m in the process of launching a new product on Amazon with my business partner and have been debating whether it makes sense to bring on a marketing agency to help with the rollout and ongoing management.

Here’s my situation:

• I have a branded product ready to go
• My main concerns are ranking/visibility, optimizing listings for conversions, and scaling ads profitably.

My business partner contacted a marketing company and they seemed enthusiastic, mentioning the product could easily get to $30K/mo in sales and $100K/mo is not unreasonable. This seemed kind of manipulative/pushy but maybe not? They would handle setting up the listing, making a website, getting product certifications approved, etc… Basically we’d only have to make sure product was kept in stock and they’d do the rest.

Th fee structure from this marketing company would be:
-Management fee: $1750/mo
-Ad spend: $1500/mo
-4% of sales over $30K/mo
-3% sales over $100K/mo

Does this seem like legit pricing?

I’m wondering if anyone here has experience hiring an Amazon agency—either good or bad. Specifically:

• Is it worth the investment early on, or should I try to learn and manage it myself first?
• What red flags should I look out for when evaluating agencies?
• Any recommendations for agencies you’ve had a great experience with?

Basically, I want to avoid wasting money but also don’t want to sabotage my launch by trying to do everything myself.

Appreciate any insights or stories from people who’ve gone down this path!