schroed9

A couple of months ago developed intermittent whining. A couple of weeks ago turned constant after 30 mph but lessened with speed. This week has turned into a humming like when you put a card in the spoke of the wheel of your bike. Only occurs with depressing the accelerator. Took it to the shop, CV boot was torn so they replaced the axle, no change. Took to transmission and they think it is the deferential and say it is a $3500. The car is worth $2500. Is this the right diagnosis? Are there other options to fix or prolong the life of this car without this expensive fix? Please help! Greg