Citing a used model isn't really valid in this case. You don't really know what kind of condition the used bike is in. If they kick on paying $500, I'd take it to a bike shop and ask them to certify that as far as they can tell, the bike was well maintained prior to the accident. That makes it more valuable than a random rusty heap on eBay. If they insist on paying the used value (I can't imagine that they would) then you insist on taking the used bike to the bike shop and having them pay the labor and parts to bring it back up to the condition your bike was in before the crash. I'm sure they'll just pay for a new bike at that point.
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Work: the 8 hours that separates bike rides.