PBS radio had a Barry Fey feature today, some rehash of his interviews over the years. One of them Fey was talking about how he first heard of Led Zeppelin, said he was promoting some other bands for a US tour and he was told he should bring in Led Zeppelin. Said he wasn't gonna pay for a nobody band, so one of the other acts told him they'd give up $750 of their money to pay for Zeppelin if Fey would give up $750 also. The rest is history.
Vanilla Fudge was the band that gave up the $750.