Why asking for the clients budget is almost always the wrong thing to do

Come again? I can hear you say. Its one of the main objectives for the first call isn't it? Find out what the client wants to buy, find out how much he wants to buy it for, then sell it to him. Simple.

True, and that advice can be good advice, but on the condition that you know the client well, and that in having done a good job for them in the past, you have built up a large level of trust.