I have the same experience with some of my clients. They expect that a website is a commodity that they can easily buy and forget about, but one that will give them a lot of leads and sales as well.

There are too many things involved in building a site, and sometimes I just don't respond anymore to requests or budgets that are too low to start with. If they are not ready to pay a decent amount of fee, then it's almost sure that they will question all the costs you will incur later in the development stage.

Just stick with a rate that you feel comfortable with and know that you will make a living out of it. You won't be making a lot of sites, but at least you'll be making sites that you will be proud of and you'll have a more sustainable business model.