That looks awesome and I definitely think that is a market for it. The interior sounds like a great idea, but I would keep them as separate figures that would either be smart props or conforming figures to the exterior so that if you're just posing with the exterior, the extra polygons won't weigh us down. Same thing goes for instance if I just want to render the cockpit, I don't need all the polygons from the rest of the plane. Even though it's a very detailed and wonderful plane, I personally wouldn't throw down more than $40-$50 for it. If you're looking for people who'll throw down hundreds or thousands of dollars for a model, then you might want to target a different community of 3D modelers. Look forward to seeing the final product.