There're 2 schools of thought here. The first one says yes you should post your rates, that way you can make sure that any potential client and you are on the same page. The last thing you'd wanna happen is to get in a discussion with someone and then find out that you charge way more than they are able to pay.

However, there's also an argument for not posting your rates where basically that allows you to tailor how much you charge based on the scope of the project. You just feel like charging a little bit more money by not posting your rates, that gives you the flexibility to do so.