I would stay away from the B4 with all the aluminium. It all looks great to beginners but it just doesn't work on the track.
One thing to look out for when buying a car is that you can run it properly. No use in buying the B44 if your local club doesn't run a 4wd class.
If you want to get the B44 check that the suspension doesn't feel wobbly and that the diff outputs are still in good condition. Then turn the transmission and make sure it turns nicely. Also make sure you can get spare parts at the track you are going to be racing at.
If your closest track is the nitro track also consider getting a nitro car. Always consider the parent factor when you want to go racing. Not all parents are so enthusiastic about driving you and your stuff to the track on a weekend...
Lipos seem expensive at first but you only really need one or two to race. Make sure your charger is ok to charge lipos and that you will need lipo saddle packs for the B44.
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