If no other market station bids it up, I would agree with the 50k.
However, if I were billing 1.5 for a station and 50k was the best they'd do, I'd be talking to other stations in the market. Healthy competition could make it 100k without much effort. Anything beyond 175k or so I'd think the station would have second thoughts about putting that many eggs in one basket.
Unless you are the next Don Imus, the station's interests would probably be better served by cutting you lose and plugging in someone else to spin the Britney tracks...