That seems to match intuition - that there are large fixed costs involved in making a rocket of any size that can reach LEO, and that scaling up the payload wou

That seems to match intuition - that there are large fixed costs involved in making a rocket of any size that can reach LEO, and that scaling up the payload wouldn't necessarily increase the R&D and other fixed costs proportionally. Then again, with increased size potentially comes nonlinearly increasing complexity requirements - multiple stages, more exotic fuels/engines, more parts to coordinate, etc. But I'm guessing LEO with these sorts of payload sizes isn't demanding enough to cause the complexity to overwhelm the fixed costs.