Anyone financed or operated a mobile services business? Asking on behalf of my wife's cousin.

My wife's cousin is a dog groomer with a loyal client base. They keep asking her when she's going mobile. So she's looking at a grooming van and came to me for a sanity check, because I analyze small businesses for a living. Turns out I know plenty about diligence and almost nothing about the economics of a $100K van with a tub and a generator bolted into it. What I'm trying to pin down for her: - Build-out cost. Is a converted used rig meaningfully cheaper than a new purpose-built one, or do the headaches eat the savings? - Unit economics. After fuel, maintenance, and the fact that you can only be in one driveway at a time, where do the margins actually land? Where's the leak? - Financing. SBA, equipment loan, something else? And does financing the renovation specifically change the picture vs. financing the vehicle? If you've bought, built, financed, or operated a mobile services business, I'd take any wisdom you've got. Especially the stuff you wish you'd known before you signed.