bubblegum said:
Any one know where the best place to get new shimano drive train parts, especially chain rings and chains is? Also is there any point in getting dura ace or is 105 or ultegra better value for money?
"Where" probably depends on what country you live in, and "best" also depends on your own wrenching skills and access to appropriate tools.
If you're happy to fit it yourself, Wiggle and Chainreaction are consistently among the cheapest online. Chainreaction prices are sometimes a little lower, but you need to spend a lot more to qualify for free shipping. Both of them are UK based, but ship fast and free all around the world - typically things arrive in Australia within 4-7 days.
If you live in the US, places like Nashbar, jensonusa, greenfish or one of the many stores listed on the "hot deals" section of
roadbikereview can be worth checking out.
"Is there any point in buying Dura Ace?" Have you no shame man? Could you honestly walk into the coffee shop and order that macchiato knowing you had <gasp> 105 on your bike?

Seriously, what everybody else said. If the money is no problem, why not treat yourself, but if you're changing from
any drivetrain pre-2007 then even 105 (5700) will be an upgrade in performance.