My rates are based on what a realtor I once became acquainted with online, charged--10 years ago. ( She charged $1 and $2/sq. ft. depending on the details being done.)
I averaged the two, and charge $1.50/sq.ft. $2/sq.ft. if I oversee major projects or contractors. OR by-the-project. Plus tax, of course.
Thus, my rates are reasonable; especially because I'm responsible and accountable for the work that gets done at the location. I also don't need to cover overhead of huge warehouses full of furniture and decor. I do have some basic decor on hand, but I provide a more custom approach.
My fees cover my design expertise, time, driving, gasoline/wear on my vehicle, hiring my house cleaners, any basic handyman work, etc. (Major repairs or contractor work, is done and charged separately through the contractor. I can oversee the project, if necessary, but will have to charge $2/sq. ft.) Fees will also cover any purchases for your home. I work with the architecture, carpet, wall colours, etc. Or basically what can't be redone before the sale/rental.
Everyone has a budget--large or small...So we work with it. Just be aware that your budget may limit us to what can be done.