Is it true that if you're buying a vehicle for less than 10,000 you don't have to have insurance to leave the lot

That was my experience I had, and if it's under 10,000 you only need liability insurance.

Customers must obtain liability or full coverage insurance as required by state law. Full coverage insurance is required for vehicle sales in Texas. Full coverage insurance is required on all vehicle sales above $10,000. Please check all state requirements before purchasing.

At least that you buy cash.