Time to rebuild my Polaris 280?

I'm looking at a $223.99 tune-up kit for the Polaris 280, but I wonder if it's overkill? The cleaner came with the pool when we bought the house in Summer 2010. It has worked fine until late last season and I have kept up with repairs like new wheel screws, tires (not wheels) and vacuum bags.
Currently, the vacuum bag is on it's last leg and the cleaner doesn't move very well. It appears that the wheels are not turning due to worn out teeth on the inside of the wheels.

My question is, do I need the full repair kit or can I just buy three new wheel and a new bag and be OK? What I don't know if there are other parts that are known to wear out. I'm OK spending $60-70 bucks to get it working with the known problems, but I don't want to then find out that there are other parts that are worn and then spend more than the $223.99 and get less parts because I bought them all separate.

Any advice or experience with this pool cleaner would be appreciated.

John