The truck is the part everybody photographs and the part everybody budgets for. It is also the part least likely to sink the business. What sinks mobile food businesses is the cost around the truck, most of which is invisible until the first month of trading.
The list that does not appear in the listing price
Commissary or prep kitchen access. Permits and health department plan review, which vary by county and can take longer than the build. Insurance, including general liability and commercial auto. Propane, generator fuel and maintenance. POS and payment processing. Event and lot fees, which in a good market are the single most negotiable and most underestimated line. Packaging. First inventory. And the working capital to run for a few months while the schedule fills.
Buy, build, or lease
A used truck that already passes inspection in your county is often better than a cheaper one that does not, because a retrofit is where budgets disappear. A new build gives you the right layout for your menu, which matters more than most first-time owners expect: a kitchen designed around the wrong menu costs you seconds on every ticket, and seconds are the whole margin at a lunch rush.
Leasing for a season is a legitimate way to test a concept before committing capital, particularly if you have not yet proven the menu at volume.
Model the week, not the day
A strong Saturday proves very little. Build the model on a realistic week: how many services, at what average ticket, at what food cost, minus fees. Then ask what that leaves after the payment on the truck. If the answer only works on the best week of the year, the concept needs another pass before the purchase does.