You've spent over $8,000 the first month of running campaigns.

You should never optimize conversion campaigns unless you have at least 500 events. The number of events you are getting at each stage of your funnel are key here:

4,000 Lead Events => you can run conversion campaigns to new audiences.

300 Add To Cart Events => you need to run traffic campaigns to custom audiences (web visitors).

121 Initiate Checkout Events => you need to run traffic campaigns to custom audiences (web visitors).

48 Purchase Events => you need to run traffic campaigns to custom audiences (web visitors).

Therefore, the only two strategies that apply in this case is to run conversion ads to new audiences to the "Lead Event" and traffic ads to people who have stayed at one of the other events to move them ahead in your client's online sales funnel.