Did you get any other prices for the same scope from another designer? That would be the best place to start with 3 prices.

Most designers get their fees from marking up the product to retail from the discount that they get from sourcing it at wholesale or to the trade only sources. 20% is a going rate. You usally don't end up paying any more than what you would by just buying retail with no assistance. If you prefer to do the by the hour bit, $100 an hour is low, as are the amount of hours estimated. $4000 is low total compensation for such a large project. Is there a cap on the fee? If you pass the 40 hours and still don't have products fnalized, what happens then?

Thanks for the feedback I am in the process of getting estimates from other designers. So far though the hourly rates are higher. The fee does not include the material costs.

With that low of a rate, and how the compensation is structured, I'd really be leery if in fact she really is a qualified designer. Or merely a "decorator". What trade groups is she a member of? Where did she receive her degree?

The best way to choose a designer is by finding a local design association and getting a list of names of members. Those who take the time to stay accredited with an association are usually the best. Try the IIDA. http://www.iida.org/

Not sure where you live, but here in So California, a lot of retail stores offer design services for free if you purchase from them. You could check that out also.

Good luck!

Suzi