Confusing: Radeon x1300, x1300pro, x1300xl, x1300xstas?

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What's the difference between Radeon x1300, x1300pro, x1300xt, x1300xstasy, and whatever other x1300 is out there? I have noticed they vary in release dates (2005-2009) and price. Is one better than the other? I'm upgrading an integrated GeForce 6150se and my psu(250 watt) doesn't have enough power to go much faster than a Radeon x1300 card. But I'm ok with that, I just want my little boy to be able to play his Lego video games and don't which x1300 to buy.