Please take a seat.
When working with a designer, make sure you understand their fee structure but know that there is no right or wrong way to charge--these are all standard and fair practices in the world of Interior Design (and any sales course will teach you, you're worth what someone is willing to pay, inflated or not!). Keep in mind that your designer is doing all of the leg work to scour their resources (some you may know of, some you may not) to find you the best furniture/accessories for your project and there are fees associated with that--both for intellectual property & actual shopping time. In the end you'll pay more than you would if you'd tackled the project on your own, but you'll also love it more.
And in my opinion, creating a home you love is always worth the investment.
(and if you've worked with a designer before, I'd love to hear about your experience!)