I'm going out on a limb here as the systems have changed considerably from what they used to be. Elite friends of mine in the early to mid 90s were doing well in $100K-$200K range. These were not the very top T&F athletes but some of the better vaulters. There are so many factors that figure into these things that numbers can get skewed very easily. If you read the great new book about Tim Mack, he won $20K in the Goodwill Games and was thrilled that he would be able to survive a year on that. Somewhere in between is the truth. I could be totally wrong but Bolt won't make $100 million no matter what he does.
In the “old days” guys got appearance fees plus bonuses. Then it got to the point that you would have to refund half of your appearance fees if you nh’d, then there was a penalty if you didn’t jump a certain height, then it was pay for expenses and places only with no appearance fees unless you were a Marion Jones (lol). One weekend at my house in Southern California I had Dean Starkey, Simon Arkell, Pat Manson and Scott Huffman over and we were discussing how this change was affecting them. Photo here from that weekend - also Jill Starkey and NeoVault's Sean Brown -
http://www.bubbapv.com/Images/poolside.jpg Pat says he’s already traveled the world many times over so it wasn’t worth it anymore to compete for prize money and no other guarantees. Huffman said that pretty much first place was Bubka and second was Tarasov so the rest were competing for 3rd place prize money – again, hardly worth it. After the WC’s in 1997 in Athens, after getting the bronze, I think Dean said he was getting $8K a meet and trying to jump three meets a week. If you got hurt you really had the squeeze put on. These guys were really smart in that they had business degrees and/or were pursuing and developing their post vault careers while they were still jumping. As a result they weren’t so impacted and are all doing very well today. Bubba