Creating a selling landing page on a turnkey basis

Hello, there.

I need a landing page for triathlon services. The niche is very narrow and you need a professional in the manufacture of Landing Page in narrow directions.

There are examples of how not to do (Landing Page with terrible conversions).

You need to study the available Landing Page, identify errors that do not allow you to get high conversion and make a good selling Landing Page.

Write an approximate time and cost.