How much can I expect a rebuild on a seized 640 to cost?

[baglock1]

I'm at work tonight and a coworker mentioned that another coworker has a 2004 KTM 640 with a seized engine that he is thinking about selling.  I emailed him asking for some details but at this point, I don't even know if it's an Enduro or Adventure.  All I know is that the engine "seized" and it's been sitting in his garage for a couple years. 

 

Assuming I need to go through the entire rotating assembly, what will a rebuild usually run?  I'm capable of doing the work myself (although this would be the first time I've even touched a KTM) but I rushed into a project bike a few months back and don't want to repeat that experience.  On that one, I didn't realize that the engine rebuild was going to be as expensive as it was.  I ended up parting it out and breaking even.

 

In any event, I've been wanting a bike that has some highway capability to extend my rides.  It seems like this one may fit the bill but don't want to be upside down on it.  I found some running bikes for sale online and the best price I found was $2000-$2500.  Depending on the cost of a rebuild and the overall condition of the rest of the bike, do you guys think ~$500 would be fair?  I realize it's a difficult question to answer with the few details I've provided but your best guess would be appreciated.  FWIW, the owner is apparently pretty meticulous on maintenance.  If true, I can't explain why the engine seized at this point.

 

Thanks for any insight you can provide.  Hopefully I'll get some more details tomorrow and can add to the thread.

[Leesrig]

Are you doing the work? And the rest of the bike better be perfect

[baglock1]

^{Yes, I had planned on doing the work.  But with that said, I think it's a non-issue.  The guy never emailed me back so I'm guessing he's having second thoughts about selling it.}