I've been running a consultancy for quite some time, and I see where the author is coming from. We used to do things like that, and still insist on paid discovery sessions before giving actual quotes.

Here's the thing though. If you've been doing this for long enough, you already know how much your business WANTS it to cost. Are you the kind of contractor who typically does $100k deals? Then you're not going to take a $2k project. And your client should know that.

All they need to know is, will it cost $5k, $50k, or $500k? And be honest, you know what kind of budgets you need to build products if you've been doing this for long enough. If your projects range from "$50k to $300k", just say that, and it will move the conversation right along.

You will thank yourself later that you didn't spend a month working with a disqualified client.