How can I Know which amount should be my "Daily Budget"?

[tanjilrahman321]

I have that feature to promote my gigs. I used that feature. But recently, in the last 2-3 months this feature didn't get much impression or clicks and Orders also. I just want to know, if I have a gig with a $85 basic price, then what should be the amount that I set for "Daily Budget"? 

1. Are there any methods? If I set the maximum "Daily Budget, " will my gig show much more than others? 
2. If I change my "Daily Budget" does it make any difference on the gig rank? 

 Please, I just want the answers from all of you guys with your past experiences. And try to make the answers authentic, so that, the others can use these method and get success on their journey.