I think your prices are way over the top.
Indeed.
If we assume that a whole season did cost ... what ... was it 45.- €?
And if we would not get a single large expansion in the future but four separate smaller DLCs (like the point updates we had so far), I wouldn't expect more than 15.-€ per DLC. And this would be already more expensive than what we payed in the past. But I guess this would be the price for the certainty and fractured content. It's always more expensive.
However, I personally believe in only one or at max two DLCs per year and I believe the same 45.-€ for a big one or 20.- to 25.-€ for a two smaller ones might be the targeted price range.
The first one will be gas giants and atmospheric planets (without prospering biospheres; primitive and sparse life might be featured). This will include new SRVs and new game mechanics.
The second one will probably open up currently locked space areas and introduce alien civilizations to interact with.
Whether they will use one or two DLCs, the content added together will be equal to what we got during a season so far.
What I could imagine though might be smaller content DLCs that add additional stuff to already (or newly) introduced features. Additional space dragons or new gas giant whales, for example.
This stuff will be relatively overpriced (when compared to the "full" expansion DLCs) and cost 5.- to 10.- € each.