For washing you would need to use either 1/2 the amount of the stuff you usually use, or get eco store stuff. But it would be fine to go into the wash (I put Josh's nappies in the wash with the rest of the clothes).
I think Baby Harmony do them, have a look there to start with. I would say get 2 (I haven't used them so i'm just guessing here) therefore if you don't get it dried during the day you have your spare one to use.
As for price anything from $30-40 would be alright (then again I haven't actually looked for them yet so i'm just guessing there).