Compare between Shortrange and Longrange

[Exodus]

but the Longrangeweapons got more range, more damage and they have low prices (acid doesnt count)

But my problem is: more DMG + more range = extreme DMG = death without any chance.

I don't get why you keep saying, that Long Range deals more damage, since it is more than obvious, that this isn't the case. Just compare the dps values between Bombarding Rockets (103), Basic Cannon (155) and Fireball Cannon (154).
They are all in the same price class, but both Basic and Fireball deal about 50% more dps.
Even when you are talking about the damage per hit, this still isn't true. So I don't see how your argument has any value, when even such basic statements are plainly wrong.