Perhaps I am naive but this conversation seems easy to resolve with just a few words. Can anyone tell me how a client would respond to this:
You can have a site with newer, nicer features, or you can have a site that supports older browsers. If you want both then you are commissioning two distinct websites. If you want usage statistics for old browsers I have them, and if you want to be economical I can produce the second website for older browsers at a reduced cost with reduced flair, after all only X% of people would see that site and it would still look reasonable, just not amazing. What would you like to do?
You can have a site with newer, nicer features, or you can have a site that supports older browsers. If you want both then you are commissioning two distinct websites. If you want usage statistics for old browsers I have them, and if you want to be economical I can produce the second website for older browsers at a reduced cost with reduced flair, after all only X% of people would see that site and it would still look reasonable, just not amazing. What would you like to do?