So, in 0.8.4, it appears that the price the popup quotes for a road/etc tile is different than the game charges:
Unsurfaced Road says 20, really 5/tile.
Cobblestone Road says 65 really 16.25/tile
Wooden Trestle Road (Bridge) says 22.5 really 22.5/tile
Masonry Road Bridge says 375 really 375/tile
Plateway says 100 really 25/tile
Wooden Trestle Rail (bridge) says 62.5 really 62.5/tile
Canal says 400 really 100/tile
Aquaduct says 112 really 112/tile
I've no means of checking whether the maintenance charges are similarly inconsistent.
Also, on what frequency is the quoted maintenance charged (monthly?)?