Remember: it's a hobby. It doesn't always have to make sense. And even things that don't make sense to you, may make sense for someone else, for various reasons.

Yes, on a pure cost/performance calculation, spending this much on hopping up a TT-02 for an open chassis class makes no sense, whatsoever. Heck, getting a TT-02 for racing in itself is not a good choice... unless class rules require it.

We have a racing series here with a class that requires an original, unmodified TT-01 or TT-02 chassis tub (blinky ESC, spec fixed timing motor, fixed gearing), but otherwise open tuning. That's what I configured my TT-02 for (and I simply cannot make myself stop half-way when hopping up any car. Once I start, it gets the full treatment. Just because I want to. And given the cheap plastic look, I was happy for every single blue part that made the car look less awfully cheap.)