There doesn't seem to be a set rule about this, so if you are talking about straight markup for retail items (furniture, objects - nothing custom made) you can expect to pay at least cost + 30% at the very least. Prepare to pay retail minus 20% and then the tax on every order. That's about as good of a deal as you're going to get these days. Some decorators will take a set % of the overall cost of the purchased items, based on their personal discounts with the vendors and not all professional % discounts are the same. Be CAREFUL! If your decorator is also your designer, be prepared to pay hefty "per hour" design fees ($200. per hour) + any mailing charges and extras that the design house doesn't include in their billing "deal". This is when you realize that it would have been cheaper and easier to do it yourself (if you have a feeling for decor and design). I once worked with a decorator/designer and before I realized it, the cost of the project came in at RETAIL + 10-15%!!! I was furious! Oh well...live and learn.

Thank you!

Good information, ko55, thanks. My wife and I were discussing this the other night and now I have some clarity. On larger homes I have designed over the years I've worked directly with interior decorators, but never had the need to get into any financial conversations with them as it seemed inappropriate.