Ignoring an issue with your roof can lead to more sever issues which can quickly escalate the price of the ending cost. In addition to this it can also increase the need to re-roof. Repairing roof prices vary on the the issue itself and the amount of materials needed. So if its a broken tile another will be needed to replace it.
Removed roof tiles, replaced the old roof membrane with a new breathable membrane and removed the old rotting wooden battens and replaced with new treated wooden battens.
Repaired the valley and put the existing tiles back on the roof since they were in a good condition, replacing any broken or missing tiles.
Broken tiles are very dangerous as parts of the tile could easily fall off the roof onto someones head or damage the gutter system.