As history has shown by forum members - some low mileage coupes can cost you the same as a very high mileage or ever worse due to the fact that Coupes do not take well being left unused for days/weeks at a time - usual reasons why it may have low mileage.
I have changed a few speedo units and from what I have seen if you try to change the mileage with out knowing what your doing then you will bugger the speedo - it can be a sure indication of some one fiddling.
A common trick is that some cars have service history up to a point so people try to change back the mileage to that time so it appears as full service history. Please note this is just for info and I have no knol of this Coupe as mentioned on eBay and thus can not say that this has happened - it may just be as described
if he rides like I think he will they'll be scraping him off the scenery in a month