In the long run, you'd expect carrying heavier payloads to be cheaper per-kg (because you're lifting more payload and less rocket, relatively speaking), but carrying larger payloads to be more expensive (because you need to be using a bigger rocket). Those play against each other to some extent.
In the very short term a new technology is likely to be pricier than the existing tried, tested and refined version (especially when you include R&D costs), how long it stays that way is hard to predict.
In the very short term a new technology is likely to be pricier than the existing tried, tested and refined version (especially when you include R&D costs), how long it stays that way is hard to predict.