I usually get 75% or higher, but, then, I only bid on things that are a good fit for our product mix, and, that, due to our equipment, have a reasonably good expectation that our price will come in below average. I stopped responding to open or online RFP's years ago, and, yet, we still seem to be growing and prospering.
Don't forget, other than pricing, there are many other reasons why you may not win a bid:
(1) The project never came to fruition
(2) They already had a vendor in mind, and, were just putting out bids to comply with corporate protocol
(3) They are unethically using you to get their preferred vendor to drop their price.