Luring in the Prospects

Last week, I engaged a visiting tradesman in the standard patter. "Yes, I work from home," I said, "and I do tax for small businesses." Pause. "Who does your tax?"  He was a lovely chap and would make an ideal client. He said he was thinking of changing, as his current accountant had moved a long way off, and it would be handy to drop off his paperwork to me instead. He then asked how much I charged. I said £600, but if he needed book-keeping the charge for tax would be lower and we needed a meeting to talk it through. He went off with my card and said his wife - who is the finance brains - would call me.

As he left, my heart sank. I had handled the whole thing badly, and I don't expect for a moment I will be hearing from him again, as I suspect a bald quote without any investigation of what he needs etc is completely the wrong way around.

How do you deal with tradesman prospects when they ask "how much do you charge?" before you've got them to agree to a meeting, and is it feasible to state that you would have to see their paperwork etc and have further discussions with them before you can comment?