The x3 440 would struggle. If you already have an AMD platform you might want to consider a quad core (955 or 965) -- these aren't the best when compared to the rest of the field but they are capable of giving you a good gaming experience.
Do i really need more than a AMD Althlon x3 440 for hi end gaming?
If you mean playing 64 player multi player maps on BF3 at ultra high settings then yes. The Athlon is pretty slow and weak compared to more modern processors. If you pair it with a high-end video card the Athlon will be a bottleneck in the system.
i just dont want to spent more money than i have to
If you have an Athlon paired with a 550Ti you don't have a balanced computer. The key to having a good gaming computer is balance between CPU and GPU. If you have a 550Ti or anything higher you want at the very least an I3 or Quad core Phenom II.