text: where do i stand legally if i damage something of yours...? say i borrow your bike and have an accident. you are a bike dealer and are familiar with the cost associated with fixing this bike. we look over the damage and concur that it is slightly damaged and should cost about a $100 to fix. a couple months later you fix the bike and send a bill for $1000. is the person entitled to the $1000?  what if the bike dealer rents out these bikes as a business and the bike was never in that great shape to begin with. can the dealer replace a whole bunch of parts with new parts actually costing $1000 or would he have to consider the depreciation and condition of the existing bike when calculating what you actually owe him. for example if one of the frames was already dented and you put another dent on the same frame, can you be made responsible for the replacement of the frame as if it were brand new? in most jurisdictions, you would be responsible for the lesser of either the reasonable cost of repair or the diminution of value.  they are going to have to explain how the cost of repairs jumped by 1000%.