(However this general principle doesn't hold if you service clients from a lower socioeconomic background. To them it's important to appear successful by displaying outward signs of wealth.)
I once worked for a plaintiff side medical malpractice firm that had extremely shady business behaviors. The offices were lavish with marble floors and fireplaces, expensive Oriental rugs, etc. They drove top-of-the-line cars. Their client base was mostly drawn from people in the lower socioeconomic strata, and I guess these kinds of trappings impressed them. However, having worked for them, I know that they charged their lunches to files every single day, even if they were eating just across the street, charged for every single fax and photocopy etc.. IOW, they nickel-and-dimed their clients, which reduced the size of the checks their clients received when they won their cases. I lasted there about five months - and if I ever needed the services of an attorney who charged on a contingency fee basis, you can bet that I would ask a lot of questions about whether they were going to be charging for things like this. (The law firm I work for now does not charge for regular mailings, faxes, phone calls and photocopies unless the number is excessive, which they determine on a case-by-case basis.) I think it does indeed depend on your client base whether having the trappings of wealth impresses them or turns them off. I would wonder if clients were being overcharged in order to allow these professionals to afford their Jaguars and their Mont Blanc pens. Someone else might think, "Gee, these guys must be very successful to make so much money."