Right now you are getting completely scammed when repairing stuff.
For example:
You have a wooden wall that has 240/250 hp, if it originally cost you 6 ruby and 1 wood (with 30% cheaper walls), you have to pay 1 ruby and 1 wood.
Why are we paying 1 wood for 10 hp, when we also pay 1 wood for 250 hp??? Make it it least require the wall to be like 125/250 hp, before asking for wood!!!!!!!!!!!