Instead, price your services at something you're comfortable with. And if you need to adjust, scale the project with the fee instead of dropping your fee.
I think the author is correct in recommending fixed price projects. It gives you a lot of room for scaling the project if it turns out the client can't afford your fee. If a client responds to your proposal by saying that they "can't afford your quote, can you lower it to make it work with their budget," you can respond by letting them know you can't lower your fee but you can take some aspects of the project out to get the price into their budget.
This has the added bonus of forcing them to see the value of the work you do. They may decide they don't want you to scale it down, that they need the full project for success and in fact they will pay you the full fee.