Just got a new (to me) propane grill, looks great, but didn't come with a tank. I can purchase one at Home Depot for $30, and a local place fills them for $21. But there's also all the exchange places, where you pay $50 for the first tank and then $20 each exchange. Seems like a wash, right? I like the idea of owning my own tank, but I imagine if I pay the $50 at the exchange place and never return the tank it's essentially mine anyway. I guess I could look for a used tank and save a little $ but I've read that they need to be re-certified every 12 years and it just seems like more of a hassle. And I do like the idea of being able to go to Walgreens just about any time of day to get a new one, where as the refill places tend to keep to more normal 9-5 business hours. Thoughts?