Anyone have experience renting tanks?
Renting is not a bad way to go. From what I've read, renting tanks is the cheapest way to go unless you're going to drink LOTS of beer. The killer price for owning isn't just buying the tank. Every five years, you have to have the tank pressure tested to insure that it will still hold pressure. Refill companies will not refill your privately owned tank unless it has had a pressure test within the last five years from date you are asking them to fill it. According to one place I went to (Cigna) - the test costs $20-50 plus shipping to the testing facility and back (steel obviously costs more in these cases). And if the tank fails the test, you're out of a tank. Do not pass Go, Do not collect $200. Return to square one.
If you rent, the costs of testing are figured into the refill price (plus some profit for the rental company). That's why, for example, an exchange costs $32 (as one guy posted above), but a refill only costs about $20.
The real question about buying a tank or renting one is a question of volume - will you be going through enough beer fast enough to justify the up-front costs of buying a tank (and paying for testing every five years)? If you're only going to go through one 20# tank a year there's really no need to buy a tank - you'll save money by renting with no downside.
If you're going to go through 2, 3, or 4 20# tanks a year, you need to start doing some math and see which one is better, cost-wise. Remember that in rentals, you would get your deposit back. Buying a tank, you could probably also recoup most of the cost of the tank if/when you sold it.
Also - don't forget what size keezer/draft system you're going to use - do you throw multiple big parties every year? The guy at the refill station told me that a single 20# tank can serve about 15 kegs - and he was talking about half-barrels (15.5 gallons). I told him that I would be carbonating the beer as well as serving it, but it's worth considering that by that same logic, a 20# tank should be able to serve around 45 full Corneys before it needs a refill (assuming no forced carbonation). On my current brewing schedule, it will take me a year to brew that much beer, let alone serve it. So, since I split my beer with a friend, and considering I'll only be carbonating half my beer with a tank, I will likely be going through only one (possibly two) 20# tanks a year.
The other consideration, of course, is your own personality and your available resources. I am a completist and like to own things - I also had the money laying around. So even though I KNEW it was not the most economical option for me, I purchased a tank anyway.
Go figure.
PS -- Re-reading my post, I realized that you might have thought that there is some type of periodic rental payment on tanks - like a monthly fee. This is not the case where I live (Midwestern United States). Here, when you "rent" a tank, you buy a full tank from a local gas supplier. If you don't have an empty tank to give them in exchange, then they charge you a rental deposit. If you bring in an empty tank and don't want to exchange, they will refund your rental deposit - but be beware. Some businesses do not refund deposits without original receipts, and others don't refund them at all. Other than that, there's NO monthly fee - you only pay again when you exchange again, and the second time, you won't have to pay a deposit, because you're bringing an empty tank in. It's like purchasing a keg of beer from a local liquor store.