That depends on how you source your bedding.
Tree-trimmer chips are often free by the truckload.
Buying bagged mulch (PLAIN, not dyed and without fertilizer or other additives), can get pricey.
Where, in general, are you located? What sort of climate?
The best way to check the drainage in a potential coop/run site is to go outside in the next really torrential downpour and look to see where water is running and where it is pooling.
If the water runs off the concrete, doesn't channel...