That's called a spring tooth harrow. If the ground has already been plowed with a moldboard plow, chisel plow or disc harrow or if it has been tilled, the spring tooth harrow will do a fine job of smoothing it out. But it is a secondary tillage tool, not a primary tillage tool.
Also, some of it depends on what type of soil you have. If you have sandy soil or a sandy loam, it will work better than in the thick, black, gummy, hard-as-concrete clay we have here. But even in poor soil it will work fine as a secondary tillage tool if the soil is dry and has been plowed as I described above.
For $250, I'd buy it. Understand, however, that it is a drag-type implement, meaning that you just drag it where ever you want to use it and you drag it through the field to use it.