Yes? And as it should be, would you not think?
They are both multi-purpose, one costs 300k, the other 56M. I'm confused at your post.
Would you buy a T9 and then think "well, but now the hauler is useless to me, that's not right"... ?
I disagree. The T9 and the Hauler are:
1) Both traders, and for a trader, a big cargo hold is VERY crucial. The Hauler is a joke compared to the T9 in those terms.
2) More "far away" from each other in terms of mass and tech, than, say, the Cobra and the Python.
Also, the Hauler can jump further than a T9, but given the fact that the Hauler can haul like what, 50 times less cargo, and 2x longer jump is nothing. So yes, the T9 is superior to the Hauler as a trading ship, in every possible way.
But that's kinda irrelevant, because when we talk about trading ships, we only compare cargo holds and jump distances, because that's what makes you money. What I'm trying to say is that when it comes to COMBAT ships (multi-purpose too, cuz they also can pack a punch), the difference is not so simple - I mean, sure, the Python, being larger than the Cobra, MUST be able to hit much harder and take more damage, but it doesn't mean that it should also have superior speed and maneuverability: it's MASSIVE, unlike the rather small Cobra. Like Poseidal said, you can only make bigger engines to gain power to some extent - at some point, the heat emanations and increased mass will cancel out the positive effects (i.e. the power gained from making it bigger will all be spent on moving its own increased mass).
Also, big ships are more expensive than the cheap ones not so much because they're superior technologically, but because they are much larger - bigger guns, bigger hull, bigger everything, which means more materials required to build that thing, etc.
tl;dr;
IMO, big ships should be able to "kaboom" smaller ones in a few shots and shrug off the fire of a few tiny pew-pew lasers/machineguns entirely (huge guns, tough shields, thick armor), but should also steer like a cow and accelerate slowly (top speed can be high, due to huge thrusters, but acceleration/deceleration must be slow, because of the mass). That's both gameplay balance and common sense (weight is zero in space, mass is not).
P.S. Python's shields should be nerfed - they're ridiculous. I'll find and post a vid where a guy on a Python with zero pips to shields rams and kills an NPC Pyton with 100% health, without even having his own shield fail. It's stupid - you can't ram a 500-ton chunk of steel into another and go through it like butter, even considering the "magic" shields.
Update: here's the vid that I was talking about (the title says "ramming a Python with a Python" in Russian, nevermind that):
[video=youtube;NhD54GwJV0Y]https://www.youtube.com/watch?feature=player_embedded&v=NhD54GwJV0Y&x-yt-cl=84503534&x-yt-ts=1421914688[/video]
