Is it effective to mention project cost in your resume?

It is effective to say whether you managed projects within approved budgets, and how you managed deviations.

You should refrain from mentioning the costs in ur resume - because this is confidential and sensitive detail.
This inevitably leads you to divulge the industry type or worst still the customer name - both of which are best kept hidden (owing to NDAs or UC requirements)

i think so because project cost gives a good idea about the broject

Yes, it gives an idea about the size of the project hence its complexity.

......Some how

yes