Pick some aspect of his job, and say the same of it ("Accounting? That's just addition and subtraction!" "Sales? That's just going out drinking").
If he gets offended, just smile.
If he gets offended, just smile.
If only we could _counter_ their "that's easy" with a similar statement of our own thrown back at them...
Something like;
-Hey Mr. Developer we need to implement feature X. I think it's a 5 minute thing really. You only need to Y and then we're set. Should take an hour or less. Probably less if you just insert and if statement in module Z.
-Sure thing Mr. Manager/Sales/What-the-heck-do-u-really-do-around-here-anyways-guy. But may I ask... Do they [the customer] really need this feature?
-What do you mean? They asked for it specifically and besides they're paying us in gold.
-Well instead of implementing this feature can't we just convince 'em [the customer] that they really don't need this feature and would actually be better of paying us 10x what they do today? That's just simple sales and accounting! I bet all you need is a phone call. That way we could play Pong all day AND make more money.
The most important thing to convey is that you are both bringing value to the table, and neither of you can do it without the other. If that is a problem, find someone else.