S.V.
I had a couple of toddler beds only because they were given to me. Then I ended up getting two full size bedroom sets for my daughters.
I wouldn't waste the money on a toddler beds. I would either buy a twin bed or a day bed. When I had the full size beds I bought a couple of bed rails to hold them and they worked great. I pushed the bed against the wall and the rail on the other side. I put a step at the bottom of their bed right next to the bed rail and the foot board so that they could get back in by themselves once they got out.
For my son we have a twin bed that we are going to use. I will do the same bed rail thing for him once we move him out of his crib.
American Furniture Warehouse is pretty inexpensive. I got my sons bed at Babies R' Us. There is also Furniture Row with several stores that I would think would have something. I know that the I-25 stores has several stores all around Furniture Row that would sell beds. But I woudn't spend a ton of money only because there is going to be a lot of wear and tear on that bed. It will go through crayons, markers, stickers, food, you name it. The mattress can just be a plain jane mattress too. Just something that is firm.