I usually use the "car warranty" analogy. That "free" 3 year service plan is not free. It's just built into the price. We're just more transparent, that's all. I like you're "typo" example as well.
The "facts of software development" is really important, especially if the client hasn't got a lot of experience in developing products. I've always found the more experienced a client is, the easier they understand the concept.
Yeah, I try to only take clients that have been in the game for a few years - or really go heavy on the "facts" speak...
Most clients are reasonable, but the newb ones simply don't know the realities and mechanics.
And it's when you have a different view on reality, that you get unhappy with each other...
I also tell my "newb" clients, that the first project is perhaps 50% of the total, even if it delivered on time and on spec (for bigger projects)... But the spec is always incomplete and wrong, so fixup is going to be needed, because we learn while we do the first version and the first "real deployment"...
The "facts of software development" is really important, especially if the client hasn't got a lot of experience in developing products. I've always found the more experienced a client is, the easier they understand the concept.