Ultimately you have to strike a deal. I think most consultants like long term engagements/commitments, but how do you set about pricing them so that the client sees it as fair and you maintain a regular income? In particular, how do you do it in response/support siutuations.

I have a situation where a client wants to make a long term commitment to me, but wants a discount. If it guarantees an income I am happy to look at this.
e.g. he will probably use me for 4 days a month. My problem iswhat happens if in some months he doesn't? He has the benefit of a discount, but I have no income. Do I set a minimum fee per month and work on a use it or loose it basis, do I allow him to carry forward some of his unused time?

Ideally I will only allow him to commit to what he will actually need, but until we start working together and better understand his requirments I am not sure how to set about this other than go for a minimum.

How have other people coped?