Brick station building
cost: $2,125
maintenance: $200
capacity: 85pax
Wooden station building
cost: $625
maintenance: $220
capacity: 50pax
---
Wooden platform with roof
cost: $600
maintenance: $170
capacity: 42pax
Wooden platform
cost: $187.50
maintenance: $80
capacity: 0pax
---
Seems a bit high?
For comparison, the platform with roof would end up being cheaper than platform + extension.
$800 cost and $300 maintenance for 50 pax
vs.
$600 cost and $170 maintenance for 42 pax
For the extension to be favourable, it might be better to reduce wooden platform from $80 to $50 maintenance and reduce wooden building to $120 maintenance.
I'm rather ahead of you on this one, in that the station/extension prices have been completely rebalanced on the Github branch for the next version. Thank you for spotting the anomalies, however.