If, given you are at the beginning of the "do onsite interview loop" stage, you have a 30% chance of getting an offer, you will need to do NINE of those to have a 95% chance of having gotten >= 1 offer.
So yeah that is kind of a bad deal assuming you already have a full-time job and/or family/kids. I guess if you're single and unemployed then it's not so bad, aside from the fact that being unemployed greatly cuts your bargaining power?