Hellobee Boards

There isn't really a wrong option. We moved our first to a crib and stayed there until he was well over two. Now at 3.5 (and 40 inches tall!) We need to buy him a big bed because he's in a toddler bed which is a crib size mattress. He doesn't seem to mind it though.
But our second child got moved to a queen sized floor bed before she turned one. That's worked well for her, too.
In general, I think that if you transition to a bed before a child climbs out of the crib, they often tend to treat the bed like a crib and not climb out.

Real bed at 2. You can always get a rail or two for the open sides of a twin or full bed

I think I would just save the money and move to a regular bed. You can put guard rails on it. DD is 2.5 and we converted her crib to a toddler bed because she was climbing out, but if we hadn't had that option we would have just put her in a regular bed.

I'd say real bed at 2 (we transitioned at 2 but from bedspring) unless you plan to have another and would ditch the mini crib and let the baby use a real crib...

I guess it depends on if you think your guy will end up climbing out of the crib soon. If not, I'd get another crib. My LO will be 3 in a few months but I don't think he'll ever climb out. He's way too cautious. So I plan to keep him contained in the crib for as long as possible, which will probably just be until he outgrows it! You can find pretty cheap ones at IKEA that are durable.