Think of it this way, if you were to purchase a G wagon IRL, you'd do your due diligence and find out that the costs of maintaining such a high-end vehicle are substantially high. This also implies that purchasing an expensive car isn't just a matter of paying a one-time fee but rather a continuous commitment, there's the luxury taxes, vehicle services etc... that'll cost you a fortune which means that if you don't have a deep pocket there's no point in investing in such a car. In our case here, a Bullet is considered a pretty good vehicle and because this is a game, you can't get taxed. On top of that, your vehicle needs no servicing (apart from occasional repairs which have a minimal cost) which in an ideal world, it otherwise would. So keeping something luxurious has to come with its drawbacks, in this case, high recovery fees.
If you ask me, Bullets should have higher repair costs and such but that would probably mean going a little too far so it's fine the way it is.
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