We bought from metalgardenbeds.com. They were expensive, but fairly easy to assemble and they seem like they may last awhile. We've had them three years. We also built our own, using leftover metal from a building project. All of the metal ones we have are fairly tall, which allows for lots of good soil, but you need a source for good stuff to put in them. In one, we threw in a bunch of rotten limbs and firewood, then straw, cardboard and topsoil. Always experimenting.

I can tell you that raised beds, certainly the fancy-pants ones (just kidding!) you're considering, are the way to go for a lot of plants. I can see a lot of merit in them. How much are they and what size, if I may ask?

They are now $146 for 80" x 40" x 17" deep. There are more options now at that vendor. The ones we designed ourselves are various sizes, up to 36" deep.