Most of them are just clueless. They either have no concept of the work involved or they genuinely believe that their idea is a precious thing on it's own and a

Most of them are just clueless. They either have no concept of the work involved or they genuinely believe that their idea is a precious thing on it's own and are doing you a favor by sharing it. They tend to go on remaining clue-deficient as most people have a hard time saying "no". As to how to deal with it: Take their offer and add to it until you'd be happy to do the work. Tell them you'd be happy to do the work for $X. Don't think of it as being assertive so much as being honest. Remember that you're under no obligation to haggle.