Short formulas to know if your offer will work, with regards to CPM (this is for SaaS companies, who are targeting correct audience):
Unit is unprofitable: 83*CPM>Price
Price is the yearly price of the offer. If you have monthly subscription, use 10*Monthly Price (if churn is below 5%), 4*Monthly Price (if churn is around 25%), 2*Monthly Price (if churn is 50%), just use Monthly Price (if churn is 80%+).
You need high ticket price to combat high CPM, in simple terms - you need to provide a lot more value than other people who are marketing to your audience.