Little do you know, you can order those insanely expensive curtains from an online wholesaler at a much lower price. And that leather couch? Unless you're adamant about having the real thing, imitation leather looks just as nice and will help you cut down on your spending.
Talk to your decorator about your budget from the very beginning, and be very direct with how much you're willing to spend -- including taxes, fees and shipping charges. If you've fallen in love with an item that's way over your budget, talk to your decorator about finding a similar, less expensive counterpart. That's the beauty of hiring a pro; she'll know of something that fits your ideal décor scheme or lead you in an equally gorgeous but more attainable direction.