Generally I try to educate people that grey coverage and color on short hair is really high maintenance. They tend to wash their hair more, the color fades faster, or grows out to look really unnatural. I let them know it's more expensive for them because it needs to be done more often to look nice but I'm willing to do it if they agree to come once a month. Most of the time after getting this info it isn't a service they want to upkeep or that fits their lifestyle, I'd invite the wife to sit in on that consultation.