Walmart offers the Prestone Extended Life Prediluted Antifreeze/Coolant 1-Gallon Jug for $8.88. Opt for in-store pickup to dodge the $5.99 shipping charge. That's around $7 under what you'd expect to pay in your local auto parts store, although we saw it for $4 less last August. It's suitable for almost any car or light-duty truck.
Vinegar is arguably the most versatile product in your house. If you aren't using it for all of these purposes, you're probably wasting money.