Most things I need from the hardware/DIY store, I can bring home in my car. With the seats folded down, 8-foot lengths of timber aren't much of a problem.

For the rare occasions when that wouldn't be feasible, they'll deliver for a moderate charge. It would make no sense to pay all the costs of keeping an extra vehicle (or a much larger one than I generally need) just to avoid a couple of deliveries per year.