How to estimate budget for inmail ad campaign on LinkedIn?

The estimate will depend on the basis of your targeted audience , keep the bid slightly lower than suggested for that particular set of audience , and Running CPS campaign is expensive on LinkedIn , keep a higher budget for 2 or three days , see the results through analysis then accordingly set the budget higher or lower

Read more here – https://business.linkedin.com/marketing-solutions/sponsored-inmail

https://www.linkedin.com/pulse/understanding-cost-per-sale-cps-affiliate-marketing-charles-nguyen/