I'm honestly really curious to see what the statistics are of freelancers who win jobs based on boosted bids. I'm seeing boosts over upwards of 50-500 connects and that just seems super ridiculous to me.
Nothing guarantees you an interview.
I often bid quite a bit higher than the posted budget and get interviews, but I only bid on jobs where I am confident that I will either be the best choice or one of the two or three best choices for the gig--I think that's more likely the reason I get the interviews.
I believe you need to estimate the project and measure the complexity of the job. This is required to ensure that you are able to delivered the project based on the timelines which project requires and you think can be done.
Now coming to the cost part, this depends on what is the pipeline you have in place for the project work. If you do not have enough work or sufficient work than you can consider discounting the cost to the customer (Similar to Sale) to be cost competitive to other bidders.
If you have sufficient pipeline than you can quote higher rate depending on the skills match to the project. If you are SME (subject matter expert) client will be willing to pay higer rate on the project.
My recommendation is to take call on rate on case to case basis. As in some of the example given above.