I would bet you are not dealing with truly wealthy people. My guess is they are Dr's, Attorneys, Dentists, Realtors and the like, they are mortgaged to the gills and are always one step away from bankruptcy. I had a great client sold his home to a Dentist, the new owner had no clue what the costs were to maintain such a property. I did a service call and filled up the fertilizer injector sent him the bill and two weeks later followed up with a phone call. He wanted me to carry the bill for two months. I was in disbelief and told him as much "you just bought a 2.3 million dollar house you are leaving for Mexico for a week and you want me, the gardener to finance 400.00 for two months, are you serious, you must be joking" He paid but it taught me a lesson the really wealthy people are great they don't look twice at the bill and pay promptly. As part of an exercise my business coach had me ask the clients I felt most comfortable with why they used my service. I expected to hear that it was because of our complete service our expertise, but my best client summed it up she said I ask for something and you get it done. And I never give her a bid I just do the work and send a bill. Check the county accessors office and see if you clients financed their home or paid cash, that will give you a start in the right direction, if you are really curious. Wealthy people pay cash, read The Millionaire Next Door (and a million ain't what it used to be).